My Little Sister Suddenly Confessed to Me, but What Am I Supposed to Do by Dating My Little Sister? - Chapter 105 & 106 & 107

Chapter 105: Homework with Mitsuki

“Sentencing! The defendant, Onii-chan, lied to us, went to Shiroi-sensei’s house to be treated to dinner, and eventually became the ‘meal’ himself! This constitutes a grave act of betrayal!!!”

In the end, I was forced to spill everything… Is there anyone who can win against these two? I told them a thousand times I wasn’t Shiroi-sensei’s “meal,” but it seems the principle of “innocent until proven guilty” doesn’t exist in this house. And starting with the reasoning before the verdict… how professional.

“The formal sentence: Onii-chan is sentenced to one full day of being ‘at our total disposal’ for each of us.”

“Total disposal… as in, anything?”

“Yes, anything, Niichama.”

The two of them were beaming. Anything…

“I mean, that’s fine, but… please keep the R-18 rules in mind…”

Then Shiori and Mitsuki started playing rock-paper-scissors. After twenty-three consecutive draws, Mitsuki finally won the right to take me out for the first day.

The next day, Shiori saw us off with tears in her eyes once again, and Mitsuki and I left the house together.

“Um… Mitsuki… you stopped wearing the black Gothic Lolita outfit?”

“Yep!”

I hadn’t asked, but I suspect she wore those black clothes like mourning dress to keep others at a distance. That was just my guess, though. It seems she actually likes the style, too.

Today, Mitsuki was wearing “White Goth.” Apparently, she took some of Shiori’s old clothes and hemmed them herself. After a few dozen minutes on the train, we arrived at Ueno Station and walked into Ueno Park.

“Niichama, first stop is here.”

“I mean, it’s a perfectly normal place for an elementary schooler, but… it doesn’t quite match your outfit. You’re getting a lot of attention, mostly from foreign tourists.”

The place Mitsuki led me to was the National Museum of Nature and Science.

“Niichama, although it says ‘National,’ it’s actually an Independent Administrative Institution. Legally, it’s a ‘facility equivalent to a museum’ rather than just a museum.”

“Hee~h…”

“And do you know what ‘Onshi’ in Ueno Onshi Park means?”

“No clue.”

“It means ‘imperial gift.’ It signifies land granted by the Emperor or a lord—in this case, the Tokugawa family. This is where Tokugawa Iemitsu built Kan’ei-ji Temple, which was later granted to the public.”

“Hee~h…”

“Oh! A locomotive!”

She spotted a train near the entrance.

“That’s a D-51. Look, Niichama, it has four driving wheels. In steam locomotives, we call them ‘drivers.’ The leading letter is determined by the number of drivers: ‘C’ for three, ‘D’ for four.”

“…Hee~h.”

Is she serious? Am I really entering this museum with a walking human Wikipedia? Is my pride going to be shredded? What kind of punishment is this…? Ah, right, this is the sentence.

The museum is split into the Japan Gallery—a beautiful old building designated as an Important Cultural Property—and the newer Global Gallery. Unlike Mitsuki, that’s about the extent of the explanation I can manage. And then…

“Niichama, iPS cells are ‘induced pluripotent stem cells’… and Niichama, neutrinos are elementary particles… Super-Kamiokande… the existence of neutrino mass… the universe…”

She went on like this after just one floor. My head started to ache.

“Niichama, the emission spectrum of this molecule is—”

“W-wait a second! Aren’t you hungry? Look, there’s a restaurant. Mitsuki, let’s have lunch.”

“Eh? Already?”

“Yeah, look, it’s better to go early while it’s empty.”

“Hmm, I guess so. Let’s go, Niichama.”

I took Mitsuki’s hand and led her to the restaurant, finally putting a temporary end to Professor Mitsuki’s lecture.

The restaurant had special themed menus, like dishes shaped like dinosaur footprints, but I went with a simple curry while Mitsuki ordered meat sauce pasta.

“Mitsuki, are you keeping up with your school homework?”

“Yeah. Even when I don’t go, I turn everything in and take my tests in a separate room. This time, all I have left is my independent research project, so I’m going to write about this place.”

“Hee~h, this place? What kind of topic?”

“Hmm, I haven’t decided if I’ll do a general observation of the whole museum or narrow it down to one theme. Based on what we just saw, maybe something like ‘The Future Development and Potential of iPS Cells.’ What do you think, Niichama?”

“Um… well… I think it’ll be… amazing? Probably?”

“Also, seeing the accelerator reminded me—the possibility of entering other dimensions via the Large Hadron Collider sounds interesting. Niichama, want to go to another dimension with me?”

“I am not going to another dimension or another world. It’s scary because you look like you could actually pull it off…”

“Tch. I thought if it was with Niichama, we could elope to the edge of the universe or another dimension…”

“I’m terrified that you might actually try that one day, Mitsuki.”

This museum was the kind of place where such talk didn’t stand out too much, but I really didn’t want an elementary schooler talking about “eloping.” I suppose her wounds haven’t fully healed yet.

Then, the afternoon session of Professor Mitsuki’s lecture began. Or rather, it was meant to be Mitsuki’s study time… but…

“Mitsuki! Come on, let’s go. Stop that!”

“No! This is a museum! I have to study properly!”

“You don’t need to ‘study’ that here! You stand out enough as it is!”

“Wait, Niichama, just a bit more… I’m different from you. I’ve only ever seen yours and my dad’s before.”

“Don’t look at mine either! It’s bad news if an elementary schooler stares at those so intently! Come on, let’s move!”

“Nooo! Wait, just a bit more! The one on the kid next to it… Kyaa! It looks exactly like yours did back then, Niichama!”

“No, no, no! That’s bad! That is seriously bad!”

“This is a museum! Let me study!”

“You don’t need to study that kind of thing!!”

I absolutely cannot say what Mitsuki was looking at, so please go to the site and find it yourself…

Chapter 106: Homework with Mitsuki

“Are you done already? We can still make it to the art museum or the zoo if we hurry.”

“It’s okay. If we go everywhere today, I’ll have fewer places to visit with Niichama next time. We can save them for later.”

“I see…”

The museum had been incredibly vast and niche. Even Mitsuki, with her endless trivia, had eventually run out of things to say in the hall filled with thousands of mineral samples, simply walking and observing in silence.

We had spent time in the lounge—which was basically a cafeteria—eating cake and tea, and before we knew it, evening was approaching.

We decided to leave and were currently sitting on a bench in front of the park’s fountain. Mitsuki watched a pigeon waddling toward us for food as she began to speak.

“Phew~ That was fun. I’ve never had a summer vacation this enjoyable…”

“I’m glad to hear it.”

It was the most hectic summer vacation of my life, but… yeah, it was fun.

“You know, Niichama… living with you and Onee-chama is so much fun. But… just having fun isn’t enough, is it?”

“Why not? If you’re having fun, isn’t that good?”

“No. Right now, Mitsuki is just escaping from reality… I’m just running away from school.”

“Running away…?”

“Yes. I think you understand, Niichama. I’m running away because I don’t want to hurt anyone, and I don’t want to be hurt.”

“…………”

“Mitsuki is weak. I can’t be strong like you, Niichama.”

“That’s not true…”

“Listen… I have three choices right now. I have to discuss them with Yayoi-chama and pick one…”

“Three choices?”

“I talked to Onee-chama about it yesterday. She told me to consult you. I think the person who understands Mitsuki best is… Onee-chama.”

“Shiori?”

“Yeah. Onee-chama and Mitsuki are the same.”

“The same?”

“Yes… we’re the same…”

“I don’t quite get it… but I should talk to Shiori, then?”

“Yeah… sorry for giving you such a strange homework assignment. But you have to listen to whatever I say today, right?~~”

“I’m still serving my sentence… even if I still don’t agree with the verdict…”

I’m innocent, I tell you!

“Once I hear the answer to my homework, Mitsuki will go back to Azumino for a bit. I have to have a proper talk with Yayoi-chama.”

“I see. That makes sense. Alright, I’ll talk to Shiori.”

“Now then, that’s all I had to say. Niichama, we still have time, so I need you to grant a few more requests.”

Wait, more? I thought it was just one big thing.

“Next… Niichama, let’s go take Purikura!”

“Again? Fine, fine. I’ll do princess carries, cheek kisses, whatever you want.”

“A princess carry?”

“Shiori tricked me into doing it once.”

“Hee~ Onee-chama actually tricked you? That’s surprising~~”

“Not really. Sneaking into my room and going through my things is a form of trickery, and hiding her feelings for so long was definitely a way of deceiving me too.”

“Hee~ Onee-chama is cute.”

“Is she?”

“Yeah, cute… and sad… Having to hide the feeling of loving someone… I think that’s very painful. I see… so Onee-chama really is just like me~~”

“What? Mitsuki, do you have someone you like too?”

“Huh? …H-huuuuuuh?! …Niichama? What are you saying?”

“Eh? I just thought maybe you have someone you like…”

“Whaaaaaat?! Are you serious? Niichama, are you saying that for real?!”

“Eh?”

“Whoa… I’m speechless. This is the most stunned I’ve been in my life…”

“Th-that much? Why?”

“I literally confessed to you at Haneda Airport!!”

“Um… ah, you said you loved me. Wasn’t that the kind of ‘I love you’ you say to a brother??”

“Right—be—fore—thaaaat! I said you should date me just like you’re dating Onee-chama, didn’t I?!”

“Well… but I told you I’m dating my sister as a sister, and technically her position is ‘ex-girlfriend’ anyway…”

“AAAAAHHH! This is why being the little sister of such a complicated pair is so hard!”

Mitsuki clutched her head. It was a rare sight for the girl who usually understood everything.

“Seriously, Niichama, you’re so much of a ‘genius’ that you go completely off the rails of my predictions.”

“Don’t use the word ‘genius’ so lightly.”

“This time, I meant it as ‘one step away from an idiot’!!”

“You don’t have to go that far…”

“You dense, insensitive, blockhead Niichama!”

“That’s mean!”

“You’re the mean one! What do you think all the effort I put into fighting Onee-chama was for?!”

“Eh? Wasn’t it just seeing Shiori as a rival?”

“Ugh… I feel sorry for all the girls who like you… Niichama, you probably don’t understand at all…”

“Eh?”

“Niichama! It takes an incredible amount of courage for a girl to say she likes someone! It takes many times more courage and resolve than when a boy says it! You’re taking it too lightly! Like, ‘Oh, I guess they like me’~~!”

“Um… yes… is it not like that?”

“Cruel… Niichama, you’re too cruel! Poor things. Everyone is so pitiable—Onee-chama, Michiru-chan, Asami-chan, and Mitsuki too!!!”

“Wait, eh? Mitsuki, me too?”

“Thaaaaat’s—whaaaaat—I’m—saying! I’ve been saying it forever!”

“Well… but I’ve had other cousins say they like me, and kids say ‘I love you’ to everyone…”

When I last saw Mitsuki, she was in second grade, and even now, I perceive her as somewhere between a child and an adult…

“Ah, this is no good… I need a meeting with Onee-chama as soon as we get home. I thought we were a step ahead of everyone else, but maybe we’re two or three steps behind… No wonder your relationship with Onee-chama never progresses…”

Mitsuki suddenly pulled out her phone and began typing at a frightening speed… Just like Shiori.

A reply came instantly. That was fast… wait, what? What are they doing? Mitsuki looked at me with a face that was almost tearful.

“…Onee-chama… Niichama! There’s somewhere Mitsuki has to go right now! So our date ends here! I’ll do the rest when we get home, so come to my room tonight!!”

Chapter 107: The Four-Party Summit

Following a sudden summons from Shiori in the evening, four girls gathered at a well-known Italian restaurant.

“Um, first of all, I’m sorry about what happened at the fireworks. To introduce myself properly: I’m Yamanoe Mitsuki, the cousin of Shiori-neechama and Yuu-niichama.”

Mitsuki, sitting beside Shiori, stood up and bowed to the two across from her. Michiru and Asami watched her with slightly tense expressions, wondering what this meeting was about.

“To get straight to the point… after talking with Niichama today, I’ve discovered his greatest flaw! I wanted to share it with you three!”

“A flaw?”

“Yes! I realized it clearly today… Niichama is… incredibly dense when it comes to romance. Like, on the level of a lower-grade elementary schooler!”

“Ahhh…”
“Mmm-hmm…”

Michiru and Asami made faces that said, “Oh, that.” Mitsuki looked shocked by their reaction.

“Wait! You two already knew?!”

“I mean, yeah. Yuu is very mature about everything except romance,” Michiru noted.

“Yeah, exactly~~ Usually, people notice when they’re being liked, but not him,” Asami added.

“Onii-chan is just exceptionally thick-headed,” Shiori chimed in.

Mitsuki slumped back into her seat, hearing their consensus.

“You three knew all along and haven’t done anything?” Mitsuki looked at them, puzzled.

“Well… it’s not really at a level where ‘doing something’ would change anything,” Michiru said with a wry smile, crossing her arms.

“That’s right~~ Right now, he seems to have the strongest ‘love’ feelings for Shiori-chan, but it’s purely as a sister. That’s why we aren’t panicking yet,” Asami agreed with a smile.

“Onii-chan won’t lay a hand on me… even though I’m ready whenever he is!” Shiori lamented.

“Yuu is too kind. No matter how much we offer our bodies and souls, he probably thinks he might end up hurting us,” Michiru explained.

“Yeah. In a way, Yuu doesn’t fully trust anyone,” Asami observed.

Mitsuki was stunned by their analysis.

“Is… is that okay with you three?”

“Well, it’s not exactly great,” Michiru replied. “I want to be trusted and loved by him too… but…”

“Exactly~~ That’s also one of Yuu’s good points, though.”

“Mitsuki-chan, do you think Onii-chan is taking everyone’s feelings lightly?” Shiori asked.

“…Yeah. Even when he’s confessed to, his reaction is just ‘Oh, okay.'”

“Onii-chan isn’t used to being liked. He doesn’t understand the weight behind it. But that doesn’t mean he doesn’t value us. He cherishes everyone. You feel that too, don’t you, Mitsuki-chan?”

Mitsuki closed her eyes, remembering Yuu’s kindness, and nodded.

“And, not to brag, but I think Onii-chan values me more than anyone in the world. But… I’m in the most disadvantaged position of all. For the reason Asami-chan just said…”

“Because I’m a sister… and Mitsuki-chan is a child…”

“I see… so that’s why…” Mitsuki finally understood the friendly atmosphere between the three rivals.

“Exactly. We have the advantage there, but…”

“Yeah, that’s Yuu’s weakness.”

“Still, lately I’ve been wondering if Onii-chan has a bit of a ‘loli’ thing going on~~” Shiori mused, recalling Yuu’s recent behavior toward Mitsuki.

“Ehhh? Then I’d be at the biggest disadvantage of all!” Asami, the “big sister” type with the large chest, groaned.

“But he doesn’t react much even when I hug him!” Michiru pouted.

“Michiru-chan, you aren’t a loli; you just don’t have a chest,” Shiori joked.

“Sh-shut up! I have a little bit! Want to see?!”

“Michiru-chan, stop! If you strip here, we’ll get kicked out!” Asami cried.

Seeing the three of them like this, Mitsuki suddenly burst out laughing.

“Hahaha! Hahahaha!”

“What is it, Mitsuki-kun? Is my lack of chest that funny?!”

“No, I’m sorry for laughing. I just thought Niichama is incredible, and it made me laugh.”

“Yuu is… incredible?” Asami tilted her head.

“Yeah. To be loved by such amazing people… Niichama really is something.”

“He really is,” Shiori agreed, looking at Mitsuki.

Mitsuki nodded back, then turned to the other two with a serious face. She closed her eyes and took a deep breath.

“Um… I have a request for you two… Will you… will you…”

Tears welled up in Mitsuki’s eyes. She spoke the words she thought she would never use again in her life.

“Will you… please be Mitsuki’s friends?!”

She bowed deeply. The girl who had insisted she didn’t need friends was now asking for them. Michiru and Asami looked surprised, then glanced at each other and nodded.

“Of course~~ Let’s be friends, Mitsuki-chan. But I’m still not giving up Yuu!”

“Mitsuki-kun and I are best friends now! But when it comes to Yuu, we’re rivals!”

Mitsuki wiped her tears and gave a radiant smile. “Thank you, Michiru-chan, Asami-chan! Mitsuki won’t hand him over either!”

“Hey, things are getting emotional, but you know, Onii-chan went to Shiroi-sensei’s house yesterday,” Shiori dropped the bombshell.

“What?!”

“Isn’t that… bad? In many ways?”

“Yeah. He even had a home-cooked meal…”

“That’s dangerous. Onii-chan is weak against pressure; if an adult makes a move…”

“And Shiroi-sensei is… she’s an adult with ‘loli’ features! That’s cheating!”

“Also, the Student Council President has been approaching him too…”

“WHAAAAT?!”

The four of them spent the next hour in an intense strategy meeting regarding Hasemi Yuu.

On the way home after parting with the other two:

“Did Niichama introduce me to Michiru-chan and Asami-chan knowing this would happen?” Mitsuki asked.

“Hmm. I don’t think even Onii-chan is that calculating, but the result turned out the same.”

“Niichama is amazing, isn’t he?”

“He really is.”

“Onee-chama, you feel like it wouldn’t be the end of the world if he was taken by those two, right?”

“Yeah… those two… well, three of you now… I think you’re worthy of him.”

“Mitsuki thinks so too… They’re lovely people. And you are too, Onee-chama.”

“Fufu, thank you.”

“But… if he actually was taken, could you give up, Onee-chama?”

“No. I wouldn’t give up. Never. Not for my whole life. But, if it makes Onii-chan happy…” Shiori trailed off. Mitsuki didn’t press her on whether that meant she would step aside.

“Hey, Onee-chama. I told Niichama about ‘that matter,’ so can you two talk about it?”

“I don’t mind, but I think his answer will be the same as always.”

“Yeah… even so, please. I realized today that Niichama is an even bigger existence than I thought—even more than Yayoi-chama or you.”

“Of course. You’ve got a long way to go to catch up, Mitsuki-chan! I’ve been watching him for years and I’m still not there. You were the one who understood him the least out of the three of us today~~”

“Uuu, Onee-chama is being mean.”

“Fufu. That’s just how incredible Onii-chan is.”

“You’re right. Yeah!”

“Anyway, tomorrow is my turn for the ‘sentence’~~ I’ll ask him then.”

“So it’s just ‘in case’… Onee-chama is so cold…”

“Hey, it’s my first date with him in ages! Of course I’m going to focus on that!”

“Ah! Mitsuki still has time left for her right today! I’m going to go flirt with Niichama when we get home~~ Maybe a bath together? Or sleeping in his bed?”

“Ehhh? Your turn is over!”

“Not yet! Let’s hurry home, Onee-chama!”

Mitsuki started running. Shiori smiled, reflecting once more on her brother’s impact, and chased after her.