Unbreakable

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Part 1:

It was 8am, and Mizuha's figure could be spotted in the bathroom. After putting in the hot water and adding some bath salts, Mizuha slowly stepped in and let out a sigh.

"…Taking a bath this early in the morning, am I? I must really be motivated."

Though there were times when she would take a bath this early, she wouldn't warm up the water this much. After all, that would be a waste if you considered the cost of electricity and such. But there was a reason why this economist Mizuha was taking a bath right now.

"Well, it's fine. After all, today I'm going on a date with Nii-san."

Her plans for today were a date with Keiki. That was why she was taking a bath this early and thoroughly was.h.i.+ng her body. She wanted to make herself look as cute as possible.

"…I really love Nii-san a bit too much."

If someone called her a brocon, she wouldn't be able to deny it. And also, they weren't actually siblings.

"……Siblings, huh?"

An older brother and a younger sister. This was Keiki's and Mizuha's relations.h.i.+p. Exactly because she knew that this love wasn't normal, she felt anxious. Even if she tried to convince herself with "It's not wrong at all", even if they weren't related by blood, she had wondered countless times if her feelings really should be allowed to exist. Countless times including now. However, she decided to stop hiding her feelings.

"——Alright."

After making up her mind, she pushed herself up out of the bathtub. Though she knew that walking around the house with her current lack of clothing was more than idencent, she had told her older brother to wait for her at the meeting place, so it should be fine.

For now, she properly dried her hair. After that, she put on some pink underwear and stood in front of the full-body mirror, holding the clothes that she had decided upon.

"…I wonder if Nii-san will call me cute…"

In the back of her mind, that worry was constantly nagging her. And although she felt scared from thinking about the possible reactions from her loved one, she still looked forward to it.

Part 2:

It was the morning of the date. Keiki was sitting on a bench in front of the train station in a huge, wide open s.p.a.ce. Today's weather was perfect. A bright, blue sky with no clouds in sight.

"To think that the day would come when I would go on a date with my little sister…"

His plans for the day were to go on a date with his little sister Mizuha. Of course, there were countless times when he had gone out with her before. Such as going out to watch a movie together, helping her with the shopping, or going to a café to enjoy some tea.

Now that it had been revealed that they weren't related by blood, and he had found out about the girl's feelings, Keiki was painfully aware that this date today held a very special meaning.

"…What should I do?"

But his question just disappeared into the wind, with no one able to answer him. And while he was waiting for the person he was thinking about…

"—Sorry for making you wait, Nii-san."

He heard a voice that was colored with tension and anxiety. When he lifted his head, he saw a cute looking girl. She was wearing a long, high-fitting tunic with matching shorts, and she had a clover necklace around her neck. Not knowing what to say, Keiki just stared at Mizuha, entranced.

"How… is it?"

"B-Bery cuteo…"

"In English, if possible."

"I think that it looks very cute."

"Ehehehe. I wanted Nii-san to call me cute. That's why I worked really hard on it."

"Guha?!"

When she grinned happily, the overwhelming cuteness of Mizuha sent a shock through Keiki's body and he had to stabilize himself by holding his knees.

"Huh? Nii-san?"

"…I think I might be disqualified to be an Onii-chan…"

"Eh?"

Apparently, Keiki had underestimated Mizuha's fighting strength. After receiving this much damage, Keiki was unable to get up for a while.

And like that, his date with his little sister started. As a side note, the reason that they hadn't left their house together was because Mizuha had requested it.

"It'll feel more like a date if we meet up somewhere," Were her words.

Keiki for his part could understand where she was coming from.

After they travelled by train to the next city over, Mizuha suddenly turned around when they stepped out of the train station.

"Hey, Nii-san?"

"Hmm?"

"Today on this date, I will make you fall head over heels for me."

"Goho?! …P-Please take it easy on me…"

Mizuha was probably planning to be extremely aggressive today. She was already cute when she just kept quiet, but these surprise attacks were clearly tearing at Keiki's reason.

"So where do you want to go today?"

"Hmm… I was thinking of watching a movie."

"Then I guess we'll do that."

"Ah, but I want to watch it somewhere other than the cinema."

"Where?"

"Uhm… A manga café."

"Eh…?"

Since Mizuha had asked for it, Keiki didn't protest and they made their way towards a manga café near them. A manga café has unlimited manga, unlimited internet access, and an unlimited supply of drinks at the drink bar, making it a small paradise for the average young person. And from what he had heard, you could also watch movies on the computers there.

"Two highschool students for two hours please."

Mizuha reserved their room in a dignified manner, and they were led to it. The room looked like it had been specially made for couples. It contained a small sofa and one desktop PC with two pairs of headphones. And, it was narrow. Very narrow. The room barely fit two people.

"So this is the rumoured couple suite, huh…?"

"Now now, Nii-san, hurry and sit down."

"Y-Yeah…"

After standing there astonished for a moment, he went deeper into the room and sat down next to Mizuha.

"They have a lot of different things here, you know."

"Ohh, do you go here often?"

"Just when I have the time. What movie should we watch?"

"I'll leave that to Mizuha."

"Really? Then—"

Mizuha skillfully operated the PC and scrolled through the various movies displayed on the screen. There really was a lot of variety. From action to romance, fantasy to comedy, doc.u.mentaries to films from overseas.

"By the way, is the AC not working? It's pretty hot in here, don't you think?" Mizuha asked.

"Really? I think that it's rather cool in he—re?!"

The reason his voice had suddenly cracked was because something unexpected entered his line of sight. While still going through the list of movies, Mizuha had opened up the collar of her clothes and started fanning herself. Because of that, her pink underwear was in plain sight.

"…Nii-san? What's wrong?"

"It's nothing at all?!"

"Really? —Ah, this one might be good. I've been wanting to watch it for a while, but haven't had the time to watch it yet."

"T-Then let's do that!" He practically squeaked as he looked away from the girl's chest.

"But, why a manga café? A cinema would've been enough, right?"

"Hmmm?"

After starting the movie, Mizuha leaned against Keiki's shoulder.

"In here, we can cling to each other as much as we want, right?"

"………"

Mizuha had liked movies since she was a small kid, and they had watched movies all the time while sitting on the couch. But this was the first time that both of them were watching a movie while sitting this close to each other.

"…Somehow, it feels like we're lovers…"

"…Yeah, it's really exciting."

Then the movie started, and they both watched it in silence. Inside this small cinema with just the two of them. Since Mizuha immediately put her hand on top of Keiki's, he was conscious of her throughout the whole movie, and afterwards he didn't even remember what it was about.

The next destination they headed towards was the same shopping mall Keiki had visited on his date with Yuika. After eating a light lunch at a fast food restaurant, they started window shopping. Just walking past and looking at the different stores on both sides of the walkway was plenty interesting already. Aside from various restaurants, there were bookstores, CD and DVD stores, perfume shops, and even shops for rock climbing gear. If there was anything you wanted or needed, you could surely find it here.

The shops that Mizuha frequently stopped at were tableware or tea shops. It seemed that her heart longed for household materials, rather than make-up and accessories. Keiki thought that this said a lot about her as a girl.

"Nii-san, Nii-san, it says that no dirt will get stuck on this ladle."

"It's weird for a girl like you to say that with a serious face."

"Ah, did that make me sound like an old lady?"

"No, I think that it's amazing how excited you are about household stuff."

"Was that a proposal? Are you asking me to become your wife?"

"Nope."

"If it's for Nii-san, I can make delicious miso soup every day, you know?"

"That's not really any different from how it is right now."

Almost all the food that Keiki ate was actually made by Mizuha. Even the lunch he ate at school. Of course, Mizuha had taken note of everything he liked and disliked when it came to food, so everything she made perfectly fit Keiki's tastes. If he were to accept Mizuha's feelings, and marry her in the future, this kind of lifestyle would probably continue forever—

While he pondered about it, Keiki thought that it sounded very blissful.

"…A future like that wouldn't be too bad, I guess."

"Eh?"

"I just thought that Mizuha might make a great wife. If there was an official certification for being a wonderful wife, Mizuha would surely attain it in her first try."

"Nii-san, you're not trying to cover something up, are you?"

"Am not."

He couldn't say that he was imagining a future where he married his little sister. And he didn't want to give her any false hopes, since he hadn't given her an answer to her confession yet.

After they had finished walking through the rows of household wares, they left the store.

"Ah…"

"Mizuha?"

The second they stepped out into the main walkway again, Mizuha stopped in her tracks. Past her gaze was a young couple holding hands.

"Should we also hold hands?" Keiki asked.

"No, it's okay."

"Why? We did it a lot when we were kids, though."

"This is different from back then. Even if we're not related, we're still siblings. If someone we know sees us, they might get the wrong idea."

"Mizuha…"

"I don't mind, but I would hate to be a bother to Nii-san."

"………"

She would hate to be a bother to Keiki—

That's probably why she chose the manga café instead of the cinema. To make sure that Keiki wouldn't be embarra.s.sed if someone they knew saw them. It's true that there might be people who would glare at him with suspicion if he went on a date with his little sister.

But even if she did it for him, he couldn't bear seeing a lonely expression on her face like that. He didn't even have to think about what was more important: His appearance in the eyes of society, or this girl's smile.

Standing next to her, Keiki took Mizuha's hand.

"Ah, N-Nii-san?"

"I don't care either if they get the wrong idea."

"………Really?"

Though she was surprised for a second, she tightly gripped his hand.

"It's exactly because of these sorts of things that I fell in love with Nii-san, you know?"

That smile Mizuha returned was as brilliant as her words, and Keiki changed the topic out of embarra.s.sment.

"B-But still, I never expected Mizuha to be the one who sent me the love letter."

"And I never thought that the day would come when Nii-san would forcefully lift up my skirt like that."

"I really feel bad about that, but I had no other way to find out if you really were Cinderella."

"You said it at the pool before, but what's with this 'Cinderella' thing?"

"You left your panties and the love letter in the clubroom, right? So we decided to call the mysterious sender of the love letter 'The Cinderella who dropped her panties'."

"Ahh, so that's what it was… What a horrible name, though."

"Right? Shouma thought of it, but it's too crazy."

The Cinderella who dropped her panties in the clubroom. That girl was currently walking next to her prince, giggling.

Wait a second… I never asked her what those panties were about.

A lot had happened, and he had completely forgotten about it, but this was the only mystery he hadn't solved up until now. Even know, the prince didn't know the reason why Cinderella had left her panties behind.

"Hey, Mizuha. Those panties…"

"—Ohya? If it isn't Keiki-kun."

Keiki was interrupted by a familiar voice. When he looked over at the source of that voice, he was greeted by a big-breasted, black-haired beauty who was wearing a t-s.h.i.+rt and jeans.

"Sayuki-senpai."

"What a coincidence meeting you here. Could this be destiny?"

"No, it really is nothing more than a coincidence."

"You really are no fun. Are you out shopping?"

"Eh? Ah, uh…"

"We're on a date today."

The one who answered the question was Mizuha. Not to mention that she did so while tightly clinging to Keiki's arm. Keiki wondered if it was his imagination, but he thought that Mizuha sounded a bit aggressive.

"Oh, is that so? Fufu, you two are as close as ever," Sayuki said as she returned a warm gaze.

This girl doesn't know that Keiki and Mizuha aren't related by blood. Even though Mizuha was clinging tightly to Keiki's arm, to her it looked like nothing more than siblings being close to one another.

"Why is Sayuki-senpai here?"

"I'm out buying ink and other club materials."

"You could've just told me, and I would have come helped carry them for you."

"Really? Then can I ask you to come with me right now?"

"Today is a bit inconvenient."

"Oh yeah. You're on a date with your beloved little sister, after all. Really, Keiki-kun is just as much of an siscon as always."

"Uhm… Can you not call me a siscon in a place like this?"

"Fufu, I'll ask you to help me again at a later time. As for the reward… let's see, I'll let you touch my body wherever you want."

"What… was that?"

"……Nii-san?"

"You're wrong. Nii-san didn't think about that at all," Keiki said.

"Hmmm? Is that so?"

"Yeah it is, so please don't look at me with those cold eyes."

"But Nii-san's gaze is directly focused on Senpai's chest?"

"Indeed, Keiki-kun's gaze was directed straight at my chest."

"I can't help it… That's just how all men work…"

On the contrary, it would be rude not to appreciate a good chest. But alas, the girls didn't understand that feeling at all, and Mizuha separated a few steps from Keiki. Not just with her body, but it also felt like she took a step back emotionally.

"Nii-san, you idiot…"

"Ah, Mizuha? Where are you going?"

"……Toilet," Mizuha said, clearly displeased, as she walked away.

"It seems like I was being a bother, so I'll excuse myself for now."

"Why did you even talk to us if you knew that you were going to be a bother…?"

"I mean, both of you looked so close, so of course I would be jealous," Sayuki said with a pout.

"Jealous…? Mizuha is my little sister, you know?"

"It doesn't matter who it is. You can't a.n.a.lyse a young maiden's heart with logic. If you don't understand that, you'll stay a virgin forever."

"Being a virgin doesn't have anything to do with that, though?!"

"Hmph. Whatever."

Sticking out her tongue in a cute manner, the uppercla.s.smen walked away. And as he watched her walk away, Keiki let out a sigh.

"Now then… How should I apologize to Mizuha when she comes back?"

Even though he was basically baited into it, the

"Also, the p.o.r.n magazines in my room are fine, but her b.r.e.a.s.t.s aren't? I really don't get her mindset… Whatever the case, the question is: What I should do now? Hmmm, should I try to appeal to her and say that I couldn't help it? Or should I tell Mizuha how much I love her b.r.e.a.s.t.s? …I feel like that would have the opposite effect, though."

Even if he knew the reason why she was mad, he didn't know how to solve it. Since Mizuha rarely got mad, he didn't know how to quell her anger. But then again, that was the real pleasure of going on dates. Namely, find out about a new side of the other person. Even if it was unpleasant information, Keiki thought that it was important to find out more about her.

They'd lived under the same roof for years, yet there were still sides of her that he didn't know about.

After Mizuha returned, Keiki and Mizuha went into a café inside the mall.

"Ahhhh, umm… Mizuhsan?"

"What?"

"Are you mad?"

"Not really."

"Is that so…?"

Even though she said that, she was slurping on the straw in her café au lait with a rather displeased expression on her face.

"I know that Nii-san likes big b.r.e.a.s.t.s, and I don't mind it all that his gaze was glued to Tokiha.r.s.enpai's chest. Not in the slightest. Not a single bit."

"You clearly do mind, though…"

"I don't."

"Hey, how can I help you cheer up again?"

"That depends on how hard Nii-san wants to try."

"Hmm…"

For Keiki, it felt like he was being tested.

"Alright. Today, I'll do everything that Mizuha wants me to do."

"Eh, really?"

"Men don't go back on their words."

"Then… There's a place I want to go."

"A place you want to go? Eh? —Wait, Mizuha?!"

After he was grabbed by Mizuha, she dragged him out of the café.

"…Eh? Here?"

"Right here."

"No, but… isn't this…"

Keiki couldn't be blamed for being taken aback. After all, this was a place that a male like him should never enter. Countless panties and bras were lined up on the shelves — It was a lingerie shop.

"I want Nii-san to choose some underwear for me."

"No seriously, what did you just say?"

"I want you to tell me your favorite type of underwear?"

"For what?"

"For when the time comes."

"What time?!"

"Anyways, go~!"

"Wait! This really isn't a place that a man like me should enter!"

"But it's something completely normal to do if we're lovers, right?"

"Is that so? Do men with girlfriends really have it that easy in today's world? That's quite the shock for me…"

Apparently, something like this was completely normal for couples. That was quite the culture shock for Keiki.

"No wait! Even if it's something totally normal for couples, we're siblings, right? An older brother picking out panties for his little sister is completely perverted!"

"But today, Nii-san is my boyfriend, right?"

"I know that that's the setup today, but still…"

"Then it's no problem at all."

"Isn't that logic a bit too severe?!"

"…Nii-san, didn't you say that you would do anything I wanted today?"

"Uu…"

"A man doesn't go back on his words, right?"

"Uuuu…"

Keiki's words from before were already coming back to haunt him.

"Nii-san…" Mizuha spoke in a sweet voice with watery eyes.

After she looked up at him like that, Keiki's stubbornness shattered.

"Okay! I get it already, so please don't look at me like a dog that just got scolded by its owner!"

When it came down to it, Kiryuu Keiki was a siscon. He would not be able to turn down this request from his cute little sister.

And now that it had been decided that he would have to pick out underwear for his little sister, both of them set foot into the lingerie shop. While Keiki walked forward with movements as stiff as a robot, Mizuha seemed completely calm and collected.

"…What kind of development is this?"

"But Nii-san chose the swimsuit for me when we went to the pool, right?"

"There's a world of difference between swimsuits and underwear. Besides, I had Koharu-senpai there to help me. Even the woman at the register is constantly looking over here…"

After all, all of the other customers besides Keiki were young women. And the person in question was starting to become dizzy from all of the underwear around him.

"Nii-san, which one would be best?"

"…Aren't those gray ones over there pretty cute?"

"This? So Nii-san likes them like this..? Then I'll try it on."

"Yeah, I'll wait over there for you."

"What do you mean? Nii-san has to look at me when I try it on, you know?"

"What… did you just say?"

"You have to tell me if they look good on me, you know?"

"But… it's you in underwear, you know? You're fine with being seen by me?"

"I don't mind… if Nii-san is the one…"

"Mizuhsan?"

Can you please not say that in a crowded place like this…? The older ladies and employees are all staring at me even more coldy now…

"Also, Nii-san has already seen me naked countless times."

"Countless times, you say…? That was back when we were still little kids…"

"We often took baths together back then."

That was back when he felt nothing when he saw his sister's b.r.e.a.s.t.s. And since then, Mizuha's b.r.e.a.s.t.s had taken quite the form. There's no way he could not be conscious of them now.

"Then wait a bit, okay?" said Mizuha, walking towards the changing stall with the underwear in hand.

And, a few minutes later, Mizuha poked out her head through an opening.

"Uhm… sorry for making you wait."

Even through the curtains, Keiki could see her fidgeting.

"I tried them on… b-but it really is a bit embarra.s.sing."

"R-Right? Should we just leave it at this for the day?"

"N-No. I want to keep going. I want Nii-san to look at me."

"Why is your decision written in stone like this…?"

After a short pause, the curtains slowly but steadily opened.

"………"

The scenery that appeared before his eyes was too stimulating, and it robbed Keiki of his ability to think. His little sister was currently standing there, wearing only underwear, with a bright red face. Her most important places were only hidden by a grey bra and grey panties. Her soft-looking b.r.e.a.s.t.s, her well-formed belly, and her slender back…

This… is even worse than I thought it would be…!

This was completely different from when he had seen her by accident before. After all, he now knew that she wasn't his blood-related little sister. Adding to that was the fact that she was showing him this by choice because of her feelings. Keiki was a.s.saulted with powerful feelings of stimulation and arousal.

"H-How is it…?"

"Ahhh… yeah, it really looks good on you, I think."

"Does it make you… excited?"

"It does. Of course it does."

"Is that so…? I'm glad…"

"Why are you glad about that?"

"I'm happy that Nii-san is excited because of me."

"Uuuuu?!"

Her fl.u.s.tered smile was so bright that Keiki could feel his heart imploding. Today, Mizuha was probably going all-out to try to make her brother fall for her.

"Then I'll buy these."

"Yeah, go ahead…"

After she changed back into her normal clothes, she tightly grasped the underwear as she walked to the register.

"Thank G.o.d. I will finally be freed from…"

When Keiki lifted up his head after letting out a relieved sigh…

"Ah…"

"Eh…"

His eyes met the gaze of a familiar girl, who was busy looking at the underwear lineup. It was the girl with reddish-brown hair bound together in a sidetail: Nanjou Mao. Clearly surprised by their sudden meeting, her hands, which were holding a considerably large bra, froze.

"H-Hey, Nanjou. What a coincidence."

"What do you mean 'coincidence?' This is a lingerie shop, you know? What exactly are you doing here?"

"Um…"

He certainly didn't have the courage to tell her that he was picking out underwear for his little sister.

"Well~ I thought that I might want to get a bra for myself…?"

"…"

In complete silence, Mao took a few steps back from him.

"…I didn't think that Keiki would have that kind of hobby…"

"I'm very sorry! I lied!"

This is bad… If she finds out that I came here to choose underwear from my little sister, I'll die…! Socially!

"Nii-san, thanks for waiting… Oh, Mao-chan?"

"Mizuha's here too?"

"Ah, yeah. Uhm…"

Keiki stared at Mizuha with a helpless expression on his face.

Please, Mizuha! Help me out here…!

Mizuha realized that and nodded in response.

"Just now, Nii-san was picking out some new underwear for me."

"Mizuhsaaaaaaaaaaaaaaaaaaan?!"

"Kiryuu… You…!"

After Mizuha's extremely blunt statement, Mao's eyes looked at Keiki like she was looking at human garbage.

"You know, Nii-san said 'I will pick the panties that suit Mizuha the most!', right?"

"I never said anything like that!"

"You're the worst…" Mao's gaze burned even more fiercely as she glared at Keiki. "I knew that you were a siscon, but to force your preferences onto your little sister… I've decided. I'll make our cla.s.smates call you 'Perverted older brother' from now on."

"Please don't!"

Considering Mao's connection network, she would definitely have no problem pulling it off. Just like that, Keiki's nickname changed from 'Siscon older brother' to 'Perverted older brother.'

"What a horrible day…"

"Normally, the Onii-chan wouldn't be the one who picks out the panties for his little sister," Mizuha said.

"You were the one who forced me to do it, you know…"

Because of Mao, the story about the lingerie shop incident had spread, and it had even reached Sayuki and Yuika. Shortly afterwards, he received emails from both of them. Said messages were abusive one-word statements like 'Pervert' or 'Siscon', and they came in like a tsunami.

"In the end, we didn't clear up the misunderstanding, and the nicknames were already barely stopping at the tame t.i.tle of 'siscon,' huh?"

"It's mostly the truth, so what's wrong with that? …Anyway, currently I'm only interested in Nii-san's blueberry crêpe."

"Yeah yeah, go ahead. Eat as much as you want."

"Thank you."

When he handed the crêpe over, she tried a mouthful.

"…Mmm, my strawberry crêpe is pretty good, but blueberry isn't half bad either."

"I'm sure the crêpe is happy that you like it."

Currently, they were in an open park outside. The sky was dyed a strong orange by the setting sun, and they had found a bench to sit down on, each of them enjoying a crêpe.

"Nii-san, you have some cream on your cheek."

"Where?"

"Right here."

Mizuha brought her face closer and licked away the cream on Keiki's cheek.

"…Indeed, Mizuhsan, thou canst be quite bold."

"…What's with that ancient way of speaking?"

"…Anyway, it's gotten pretty dark, so should we go home for now."

"Ah, wait, Nii-san."

"Hm?"

"Just a bit. It'll be soon."

"What will be soon?"

"It doesn't matter. Come here."

He was pulled by Mizuha, and they made their way to the front of a water fountain. Immediately after they arrived, their surroundings were wrapped in a dazzling light.

"This is…"

The fountain was illuminated with artificial lights. Even Keiki had to say that it looked rather romantic.

"The girls in my cla.s.s told me about this. I wanted to see this with Ni-san… What do you think?"

"I think that it looks pretty romantic."

"Fufu. Since we're here already, how about we take a picture?"

"Oh, nice idea."

"Then, Nii-san, come a bit closer."

"How about this?"

"A bit too far. Here, like this."

Hey, isn't this a bit…!"

Mizuha tightly gripped Keiki's arm, and her soft feeling was directly transmitted to his skin and relayed towards his brain cells. They were currently standing at a distance that only couples do. Pus.h.i.+ng out one hand in front of her, she flipped her smartphone's camera to selfie mode and showed a bright smile.

"There's no use arguing about it—Here, say cheese!"

The sound of the shutter played, and Mizuha separated from Keiki. After checking the screen, she happily smiled.

"Did you take a good one?"

"It's perfect. I'll send it to you later, then."

"……Yeah."

"Nii-san?"

"Ahh, well… I was just thinking that we might really look like a couple."

"…………Yeah, you're right."

Watching a movie together, going shopping together, taking a picture together…

—It was exactly like the normal date Keiki had always dreamed of.

Maybe, if it's Mizuha, we might actually become normal lovers….?

Once he started thinking that, he furiously shook his head.

No no no no… Even if we're not related, Mizuha is still my little sister, you know? Laying my hands on her is…

He had repeated those thoughts countless times already inside his head. Still, he was unable to find the right answer. And while her older brother was in lost in his internal conflict, Mizuha showed him a bright, gleeful smile.

"It was a lot of fun, but when I think that it's going to be over soon, I feel a bit lonely…"

"…There's one thing that I would like to know."

"Mhm? What?"

"Why did Mizuha fall in love with me?"

"Mmm… I wonder. I don't know."

"You don't know?"

"I think that the trigger was that first meeting with you… You heard about my real parents from Father, right?"

"Yeah…"

"Even though it's been so long, I can clearly remember the first time I met Nii-san."

With the light of the water fountain behind her, the girl started talking about the past.

"It was a bit before meeting Nii-san, when I was still in preschool. My parents worked at the same place, so they always went there together in one car, and they always picked me up together in the evening… But one day, no matter how long I waited, they wouldn't come."

"………"

"I waited so, so long. In the end, my parents never came home. The people who came to pick me up were the father and mother that I have right now. In the end, I was never able to say 'Welcome back' to my real parents ever again."

Those were memories from when she was still a small child.

Just how tough must that have been?

Just how lonely and how sad must she have been?

Just from imagining that, it felt like someone was ramming a knife into Keiki's chest.

"Since I didn't have any relatives I could go to, father and mother adopted me. And in that house, I met Nii-san for the first time—"

She stopped, lifted up her head, and gazed at Keiki.

"I remember it, even now. What Nii-san said to me back then. What he said to me, who had just lost the people she loved the most in the entire world. 'From now on, we'll always be together,' you said. Hearing those words, I felt so, so happy."

Her kind, thankful smile showed just how important and how special those words were for her.

"Living under the same roof, eating the same food, watching the same TV show while laughing, fighting over the smallest things, but still, making up immediately—"

Those words, drenched in her warm, comforting feelings, were transmitted to Keiki so directly that it hurt.

"As if I wouldn't fall in love with you while being so close like that."

That was the process of why Kiryuu Mizuha had fallen in love with her older brother. It wasn't anything special at all. Her feelings came about because they were always together.

"Thank you for always staying together with me—I love you."

The moment she spoke out those sweet words of affection, Mizuha brought her face closer. Even though Keiki still thought that they shouldn't do this, he couldn't pull away. He only shut his eyes, and a soft feeling hit his lips.

"……Just kidding~"

"………Eh?"

When he opened his eyes, he saw Mizuha's finger pressed against his lips.

"……Mizuhsan?"

"After all, I promised you that I wouldn't kiss you anymore."

"That's right…"

"Did you expect it?"

"D-Did not!"

Since Keiki's reaction completely blew his cover, the girl let out a giggle.

"If Nii-san is fine with it, let's go another date sometime, okay?"

…Just how cute can you be?

It shouldn't come as a surprise that the girl's smile did a lot of damage to him.

Part 3:

That evening, in the bathroom of the Kiryuu household.

While soaking in the warm, water-filled bathtub up to his shoulders, Keiki reminisced about the date today.

"The date was really fun…"

Those were his honest feelings.

Watching a movie in the manga café, holding hands while walking, feeding each other crêpes. Keiki was sure that they must have looked like a lovey-dovey, happy couple.

"The problem isn't that Mizuha is a bad girl or anything. She's cute, kind, and has big b.r.e.a.s.t.s… And she even told me that she liked me."

There was no way that Keiki wouldn't feel happy about this straightforward, impactful confession. It made him think that her being his little sister wasn't a problem at all.

"As long as she's cute, it doesn't matter if she's my little sister, right…?"

Though he called her his little sister, they weren't related by blood.

If they decided that they wanted to get married, there would be no problem at all.

"No, thinking about marriage is a bit too fast, isn't it…?!"

Feeling embarra.s.sed by his thoughts, Keiki dived deeper into the bathtub, until even his head was underwater.

He didn't even give her an answer to her confession yet.

Should he accept her feelings or not? The answer wouldn't come to him, no matter how long he thought about it.

"I feel a bit dizzy… It's time to get out."

In the end, his answer was postponed once more.

After drying himself off, Keiki put on his clothes, dryed his hair, and returned back to his room, only to find Mizuha sleeping on top of his bed.

"She doesn't know how hard it is for me, and she's sleeping with such a happy face," Keiki said. He sat down on the end of the bed, softly stroking the girl's face. "Hmm?"

Next to her was her smartphone, and on the screen was the photo they had taken together at today's date.

"Now matter how I look at it, we totally look like a couple."

Mizuha was probably waiting for Keiki to get out of the bath, gazing at this one picture—She probably wanted to look at it with him. Imagining that, Keiki could feel his face getting hotter. Trying to cover that up, he swiped back through the other photos she had taken.

"—Ahaha, when did she even take this?"

Her phone was full of photos of Keiki from today's date.

His profile while eating his crepe, his appearance while he was looking at a frying pan with a serious face. Countless pictures, only of him.

"…Does she have more?"

Though he felt bad for peeking into her photo folder, his curiosity got the better of him—

"………Eh?"

But once he arrived at a certain photo, he couldn't hold back his astonishment. What was shown on the photo was a girl hiding her eyes with one hand. The bottom part of her clothes were in her mouth, and her chest, wrapped in a pink bra, and her beautiful belly were clearly visible. Her other free hand was holding up the smartphone to take a selfie.

"…W-What is this?"

The main problem was that Keiki knew the girl in that picture. After all, the clothes she was wearing, that pink underwear, and the clover necklace around her neck exactly matched the appearance 'she' had during their date today—

"…Is that… Mizuha?"

There's was no way that he would mistake her just because she was hiding her eyes. Her hair, her lips… he clearly recognized her. The girl in the picture was without a doubt Kiryuu Mizuha.

This… is something I shouldn't ever see, right…?

HIs heart was beating like crazy, when—

"——Nii-san?"

She had probably opened her eyes around that time. Mizuha had lifted her body up from the bed and was staring at Keiki in puzzlement.

"Is that… mine?"

Realizing that her older brother was holding her phone, her cute face lost all color—

"Nii-san, stooooop!"

Letting out a shriek that Keiki had never heard in all the years that they had lived together, she ripped her smartphone out of his hands. And, after checking the screen, she fell back onto the bed, staring blankly at Keiki.

"………Did you see?"

"……………I saw."

"Ah… So I was too late."

That picture of Mizuha was already burned into Keiki's mind.

"Honestly, I'm a bit confused here… What is this picture about?"

"Don't worry. I don't upload that stuff online. I would hate to be seen online, after all… Though I would welcome it if I was seen by Nii-san."

"Welcome it…?"

Even though he should know this girl more than anyone else, he had never expected to hear these words. And, with the most lovable fl.u.s.tered smile, she said…

"After all, I'm an exibitionist."

And threw this coming-out statement at him.

A few minutes later, both Mizuha and Keiki were sitting on top of the bed, facing each other.

"It happened in the summer of my 5th year in gradeschool. We had swimming cla.s.s that day, and I forgot to bring some reserve panties, so I had to walk around the whole day without wearing any. During that time, I felt weirdly excited, and the embarra.s.sment I felt…"

"And?"

"It felt really good for some reason."

"I-Is that so…?"

What Keiki had asked her was the reason why she became an exibitionist.

"Now that you found out, I might as well show you…"

Mizuha fiddled with her phone and handed it it Keiki.

"T-This is…?!"

On the smartphone that he had received, he could see an opened folder of pictures. Pictures of her lifting up her skirt, pictures of her only wearing underwear, and even completely naked ones.

"Uhm… Mizuhsan? Somehow, that room looks oddly familiar though?"

"Ah that. I took those when I was naked in Nii-san's room while you were sleeping. My heart was beating so fast that I thought I might die."

"What kind of strip-show are you doing inside my room?!"

Here was a perverted girl, taking nudes while her older brother was sleeping almost right next to her. While he was in the land of his dreams, his little sister was in her birthday suit right next to him. Just the thought of that sent s.h.i.+vers down his spine.

"There were also times when I fell asleep inside Nii-san's room like that."

"So that's why you were sometimes wrapped up in my blanket?!"

Dangerous photos kept coming when Keiki swiped through the folder.

"…I wanted to ask about this before, but what were those panties for that you left with the love letter?"

"Ahh, I actually brought them to change into them."

"Change? What do you mean?"

"That time when we were cleaning the clubroom, I was actually wearing no panties."

"No panties?!"

Since it came out of Cinderella's mouth, it was the cold, hard truth.

"It wasn't because you forgot to put them on, right…?"

"It wasn't that. I didn't wear them out of my own free will. Sometimes I want to have this feeling of liberation, so sometimes I go to school without wearing any."

"…No-panties days, you say?"

"And, on that day, I was getting sweaty because of the cleaning… so, uhm, I was feeling a bit drippy down there…"

"…"

"So when I put down the love letter, I went to put on the extra ones that I brought, but Nii-san came back faster than I had expected. I hid inside the locker in a panic and forgot to take the panties with me."

And right after that, Keiki had found the love letter. Until he had calmed down and left, Mizuha had to hide inside the locker. Thinking back on it, Mizuha was uncomfortably fidgeting after the cleaning operation had finished. And the reason for that was probably because she wasn't wearing panties. It was because she was sweating in a place that surely wouldn't be comfortable for a clean freak like her.

"Before, there was a time when Nii-san asked me if I ever felt like not wearing panties at all some days, and I said no, but that was a total lie. I don't wear panties on a regular basis."

"Oh dear G.o.d…"

Keiki had been terribly shocked when he found out that Tokihara Sayuki hadn't worn panties for the duration of one day, but Mizuha had been doing that regularly all along.

"T-Then, why did you steal those panties back from my room? There was a possibility that I would find out about your ident.i.ty because of that, right?"

"I really liked those panties. And I felt weird knowing that Nii-san would probably use them for this and that every night."

"Just for reference, I never once used them for that, okay?!"

He wanted to emphasise that part.

"…But, I understand that you're an exibitonist, but why did you take all those pictures during the date?"

Some pictures in that folder he was shown clearly were shot during the date.

"That's… I wanted to get attention from Nii-san."

"Attention?"

"After all… Nii-san got excited by Tokiha.r.s.enpai."

"I didn't mean for that to happen, though…"

"When I get mad, I feel like stripping. Once I start, I can't hold myself back. It's like stress relief to take photos like this."

"What kind of stress relief is that…?"

Because her older brother was being flirty with other girls, she had felt irritated, and relieved her stress inside the toilet.

"You know, when I go to school without panties, or when I take these pictures, I get really excited. And aroused. Just like when Nii-san saw me in my underwear today."

That was probably the main reason why she had wanted him to pick out new underwear for her.

The prince, who had been searching for so long, had now found out that his Cinderella was in fact an exibitionist.

"Even though I'm your little sister, I would be happy if you made me your girlfriend."

"Sorry, that's impossible."

No matter how cute she was, no matter if they weren't connected by blood, a pervert was impossible for him. After all, Keiki's dream was to experience normal love with a normal girl.

All four of the Cinderella candidates who had partic.i.p.ated in the cleaning operation. He had found out that all of them were perverts, and the hope that he could get a girlfriend had finally been shattered into a thousand pieces.