I woke up bright and early on Saturday morning, feeling oddly excited for the coming day. While I viewed most weekend recreational activities with disdain, studying with a friend was hardly something that could be classified in that malignant category.

A friend... or an acquaintance? I'm not totally sure what the right term is for what Yotsuba and I have. Things are even more fraught when I consider my relationship with her sisters. Humans are complicated...

My school things packed in my bag, I left after a very small breakfast. The route to Yotsuba's place was straightforward, but a bit of an arduous journey by foot. I caught a bus, and noted with mild interest that the direct route took me right by the park to which I'd wandered earlier in the week. The bus was fairly crowded even at this time in the morning, so I huddled up with my bag in my lap, and reviewed English vocabulary from my flashcards.

"Ordinal... ordinal... that sounds like cardinal. I wonder if there's any relationship between the words?"

Before I knew it, I was at the appropriate bus stop, and I hastily pushed the button to signal that I wanted to get off. I stepped down from the bus via the back door, and looked around me for the address Yotsuba had given me.

"Where is it... where is it... ah! Ah... it's... the tall one."

I stared up at the giant building in front of me, with a sign saying "Pentagon" on it.

"I forgot... they're rich rich."

I sighed, and then made my way to the front door. Looking down at the instructions Yotsuba had e-mailed me, I tentatively walked over to the device to the right of the door -- I thought it was maybe an intercom system? -- and input the apartment number I had been sent.

There was a moment of anxiety that riddled me as the intercom made a dialing sound, and then a familiar voice picked up and said, "Hello?"

"Uh, hi. This is Uesugi..."

"Ah, Uesugi-san! Wow, you're super prompt! I'll ring you in. Just take the elevator up to the thirtieth floor, and come on in."

The line went dead, and with a bzzzt, the large glass door slowly swung open. I hurriedly made my way inside, and was flabbergasted by the grandeur of the lobby. The floor was marble, there were nice light fixtures on the walls, and the ceiling had a distinct lack of water damage. I rushed into the elevator -- I was overwhelmed.

The elevator didn't help.

The lobby had been fancy enough, but even the floor of the elevator was marble. As I pressed the button for the thirtieth floor and began to rise, my discomfort was palpable. It also didn't help that the elevator was slow. For a solid minute, I stood in place as the metal box rose. An intrusive thought about the cable supporting me snapping pushed itself into my head, and it was only with great difficulty that I forced it out.

Ding.

The door opened, and I stepped out to find myself in a carpeted hallway. Wandering the halls, I eventually reached a door which had "Nakano" emblazoned on it in what I could only presume was solid gold -- not that my untrained pauper eyes could tell the difference.

I slowly opened the door, and was greeted to the sight of a cavernous apartment. The far left wall was entirely made of glass, with a terrace overlooking the city. The right-hand wall was made up of a large kitchen, and the central area had a lounge-like arrangement of couches and a coffee table. Behind those were a table, presumably for meals, and a bookshelf. At the far end of the room appeared to be stairs leading up to a second floor, though I couldn't see what was at the top from my vantage point.

What drew my attention, however, was the green-bowed redhead sitting on one of the couches and waving at me.

"Hey, Uesugi-san! Welcome, welcome! Come on in!"

I took my shoes and coat off, and made my way into the room, exerting every ounce of self-control I had to stop myself from ogling the apartment. As I sat down on the other couch, an errant thought crossed my mind.

I'm pretty sure that balcony is larger than our entire apartment...

Yotsuba looked me up and down, and tut-tut'd, a sound I'd never heard her make before.

"You're wearing our school uniform on the weekend, Uesugi-san? The weekends are for casual clothes! Gotta let loose and--"

Suddenly, she paused, and a pensive look came over her face.

"Actually, I just imagined you in a t-shirt and jeans, and something felt really off about it. Nevermind, Uesugi-san, forget I said anything. The school uniform suits you."

"Uh... thanks? I think?"

Yotsuba was wearing a huge blue sweatshirt with "428" written on it, and jean shorts. Despite the fact I'd only ever seen her in school uniform, the look felt like it suited my mental image of her.

"Oh! I guess I should give you a tour of the place. But first!"

Yotsuba stood up, and then spread her arms dramatically.

"Behold! The snacks!!!"

For the first time, I noticed that the coffee table had numerous bowls and plates on it, though with room on it purposely carved out for studying. There were various crackers and chocolates, as well as vegetables and dips, some of which I didn't even recognize. All-in-all, it looked like all the brain food one could possible hope for.

"Well done, Private Yotsuba. Full marks on snack acquisition," I said, nodding my head. I can give her a compliment on this, at least. She really did go all out, just like she said she would.

"Eh? Private Yotsuba? Why am I so low-ranked? I thought after a display like this I'd at least be Corporal Yotsuba!"

I shook my head.

"Alas, in order to be promoted to corporal, you'll need to pass a written exam, not just make a superior snack spread."

Yotsuba sighed. "Ugh, I'll never be a corporal then. My dreams are dead in the dirt! Curse you, military bureaucracy!"

I took one of the pretzels, and dipped it in a savoury-looking beige spread. I took a bite, and then raised an eyebrow.

"This is delicious... what is it?"

"That's a pretzel."

"No, the dip."

"Ohhhh. It's called hummus, it's a Middle Eastern spread. Our dad went on a trip to Jordan for a medical conference and brought some back for us. I really liked it, so I've been getting it ever since. Turns out you can just pick it up at the supermarket!"

I nodded thoughtfully, then dipped another pretzel in a different dip, this one green. "...and this one?"

"That's guacamole. It's basically smashed up avocados."

I sat back on the couch, mildly dazed. "My eyes have been opened to a wide world of snacking that I didn't even think was possible."

These are some real rich people dips, huh?

Yotsuba had an extremely smug expression on her face.

"Indeed! I am the master of spreads and snacks. I told you to leave it to me! Hehehe..."

Then she walked out from amongst the couches, and beckoned for me to follow.

"It's time for Yotsuba's patented super special house tour! Attendance is obligatory, no refunds are available. Please, no photography."

I snorted, and then got up to follow her.

"This is the kitchen, which is, as they say, where the magic happens! Though by "the magic" they mean dinner, and by "happens", they mean Nino cooks it. Over here is our bathroom, should you require the facilities. The balcony is over this way... whoa, it's pretty windy today! Maybe don't go out there until it calms down a little bit."

The bathroom is also bigger than our apartment...

"Oh, and the last step on the tour -- the stairs!"

Yotsuba led me to the bottom of the stairs, which went up to a second floor that essentially just comprised a landing running along the length of the interior wall. There were five doors along the second floor; one immediately to the left of the steps, and then the remaining four along the wall.

"I'm not gonna actually take you up there, because that's where our bedrooms are, but our rooms are numbered! Ichika is in the room right next to the stairs, and then it's Nino, Miku, me, and finally Itsuki."

"That seems... methodical," I said, not really knowing how to respond to that.

"Indeed it is, my good sir, indeed it is! We can't go up there right now though, because Nino, Miku, and Itsuki are all hiding out in their rooms, and two out of those three don't particularly want to see you."

Yotsuba sighed, and then mournfully looked up at the doors.

"Hopefully they come around. I think it would be so much fun to just hang out and study, all of us together."

I shrugged, slightly uncomfortable. "Well, maybe one day. That is the point of Operation Twintail after all."

Assuming, of course, that Itsuki and Nino don't kill me first. If Itsuki had a knife, though, I'd be more worried about the person next to me...

"Anyways, that's my incredible tour! Please, hold your applause!"

I politely applauded anyways.

"Argh, Uesugi-san, what did I just say? You're gonna make me blush! Alas, this poor woman wasn't cut out for show biz -- I can't handle the fame! Anyways, shall we get to studying?"

"Yes," I said gratefully. Anything to distract me from the fact that two rich girls who hate me are lurking on the second floor waiting to strike. This is way more stressful than I thought it would be.

The two of us settled down in prepared spots amongst the snack spread, and began to get to work. I was on the couch facing the huge television that was fastened to the wall to the right of the front door, and Yotsuba was on the floor opposite me. Since we had the whole day to study, we started with Yotsuba's strongest subject, Japanese language arts. Both of us had progressed further into our respective assigned readings, and needed to complete analyses of the plots as they stood.

While my analysis was, obviously, perfect, it was somewhat fun to bounce ideas off of Yotsuba, and see what she thought. Though her answers were unpolished, there was occasionally a small emotional insight that I hadn't considered. Her grammar, however, was simply not on the same level as mine -- her kanji knowledge was also, frankly, abysmal.

I was starting to feel a little smug in my superiority when I suddenly heard the sound of a door opening from the second floor, and I felt my blood run cold. All thoughts of superior kanji knowledge left my head.

Oh no. They're coming. The moment of truth has arrived.

There were footsteps down the stairs behind me, coming around the back of the couches, and...

...into the kitchen?

"Morning, Miku!" chirped Yotsuba. "Glad to see you're finally awake!"

Awake? Ah, they're probably all still asleep then, not hiding. Which means... they'll probably still come down soon.

I felt vaguely like a man awaiting his execution.

Miku stifled a large yawn, and then said, "...'Finally' awake? Yotsuba, it's nine in the morning on a weekend. It's still pretty early. The thing that's weird is that you guys made plans to start studying at eight a.m. on a Saturday."

I guess we did start somewhat early... maybe we should keep the volume down.

Yotsuba turned to me in shock.

"Wait, are we the weird ones, Uesugi-san?!"

I gave her a cool look. "You're definitely a weird one."

"Ah! Betrayal! Betrayal! Shame upon you, Uesugi-san! Shame for a thousand years!"

I chuckled, and Yotsuba broke into a grin.

"Hey, Miku, do you want to join us?" she asked.

"Not to study, no, but I'm definitely taking some of those snacks."

The headphone-less girl sat down on the second couch that faced the window, and helped herself to some of the crackers. She was wearing blue pyjamas, making it clear that she had just woken up. Her hair was a bit of a mess, but she didn't seem to particularly care.

"So," she said quietly, after finishing up her snack. "You're the Uesugi Fuutarou I've heard so much about, huh?"

"Yes, that's me. Nice to actually meet you."

"Likewise."

She seems nice.

As we got back to studying, Miku sat there silently munching on the snacks (which were technically her breakfast), and watching us work and occasionally chat. About twenty minutes late, a timer on Yotsuba's phone went off, and she stretched.

"Alright, Japanese time is uuuuuup!"

"What did we have planned next again?" I mused. "Was it social studies?"

"I think so," Yotsuba groaned, stretching her back muscles. "Man, you don't realize how bad your posture is until you study for a few hours. I need to work on that! Don't wanna get stiff!"

Miku stole a few more chips and dipped them in the hummus. She then stared at me as I pulled out my textbook, munching on her snacks.

"You know," she said, licking the spread off her fingers after she'd finished, "you're not really like how Nino or Itsuki said you were at all."

I sighed. "I don't know what those two have been saying about me, but they've got a really bad impression of me. Itsuki's is mostly my own fault, but Nino's just... sort of happened?"

I turned to Yotsuba, pondering.

"What does Nino say about me, anyways?"

Yotsuba grimaced. "You... probably don't wanna know, Uesugi-san."

I winced. "That bad, huh?"

"I haven't heard you make a single evil laugh since you got here," Miku commented. "Also, you haven't said a single rude thing to me. You did to Yotsuba, I guess, but that felt more like a joke than you actually being mean."

I swung back to Miku.

"I-- wait, hang on. I don't do evil laughs."

Then I turned back to Yotsuba.

"I don't... do I?"

Yotsuba frowned. "Not that I've heard... Oh, wait, there was one time! Remember when I was super stuck on those electrostatics questions?"

I nodded. "Yeah, I made you a short worksheet for them on the fly. I had fun with that."

"You did let out something resembling a demonic giggle while you were making those questions. Man, those were hard!"

My face fell. "Oh... uh... hmm..."

Miku laughed quietly. "Demonic giggle? What the heck is that?"

Yotsuba pointed at me. "Go on, Uesugi-san! Let out a demonic giggle!"

"How the hell am I supposed to do that intentionally when I didn't even know that was something I did until now?!"

"Good point! Also, excellent use of a pun, Uesugi-san! Nine out of ten, almost perfect!"

"That was unintentional -- and also, a nine out of ten doesn't make me happy."

Yotsuba muttered something about perfectionists, and then took a chocolate from a bowl, unwrapped it, and popped it into her mouth.

"Anyways, let's get back to work," I said.

Miku pouted. "I didn't get to hear a demonic giggle..."

"I mean, I'm definitely not going to do it if I'm aware of it. I don't even know what 'demonic giggle' means, Yotsuba!"

Yotsuba winked at her sister, and then stage-whispered, "If he does it again, I'm gonna sneakily record it and send it to you, Miku. It was very demonic."

"Please don't do that."

We kept studying, and I noticed something new compared to when we'd been studying Japanese grammar. Miku seemed like she had an almost smug look on her face as we discussed Sengoku warlords. She also seemed to be actually paying attention. When we finally got to Tokugawa Ieyasu, Miku stood up, and said, "In honour of the subject, I'm going to go make some tea. Does anyone want any?"

I glanced up. "Green, or black?"

She smirked at me. "Green, obviously."

"I'll have some then, thanks."

"I'm fine, thanks!" Yotsuba called. "That stuff's too bitter for me."

Miku shrugged, and went to the kitchen to make the tea. She returned a few minutes later with two cups of tea in yunomi. She set mine down before me, and then returned to her couch to sip on the green tea. I drank mine as I worked.

This is bitter. I almost feel like adding sugar to this would be blasphemous though.

A few minutes later, Yotsuba suddenly dramatically stood up, making me start.

"Eh? Yotsuba, what's wrong?"

"Tooooooilet!" she announced, and then left the coffee table to run to the larger-than-our-apartment bathroom.

The door closed, leaving just Miku and me alone in the living room. I put my pencil down, took another sip of my tea, and then leaned back on the couch.

What was it Ichika said about Miku? Find something that interests her...

I pondered for a moment.

She looked awfully smug when we started talking about warlords... and I recognize that look. I can feel it written all over my own face whenever we have class. That's the look of someone who already knows the thing being studied. That's my face.

"Is it alright if I call you Miku?" I ventured. "Calling you all 'Nakano-san' is a bit bothersome."

Miku nodded, and then said, "Only if I can call you Fuutarou."

I shrugged. "That doesn't bother me, so go right ahead."

"Ok, Fuutarou." She said it almost like she was trying out the taste of the word in her mouth.

"Can I ask you a question?"

"Go ahead."

"You looked like you knew a lot about what we were studying. Are you particularly interested in Sengoku warlords?"

Miku froze, her cup in her hand suddenly not moving. Her eyes widened, and a panicked look crossed her face, a reaction that caught me completely by surprise. Then she said, quietly, "...What makes you think that?"

I tilted my head slightly in thought. "You were making the same expression I make when I already know what's being taught in class. There's just something about already knowing what's being taught to you during a lecture... I really like that feeling."

Miku glanced away. "Well, you're wrong."

"Ah, is that so? Sorry, then. I shouldn't have assumed."

She glanced back at me, and then raised her yunomi to her lips and took a sip.

The bathroom door flung open, and Yotsuba marched back to the couches.

"I have returned!"

I clapped. "Truly a gruelingly long journey from here to the bathroom. Commendable, Private Yotsuba, commendable."

Yotsuba pouted. "I want a promotion!"

"Pass the midterms first."

"Unfair! That's too high of a hurdle!"

"Fine, don't get a zero on the midterms."

"Unfair! That's too high of a hurdle!"

"Seriously...?"

Suddenly, a door slammed open on the second floor, and a redhead leaned over the railing, glaring down at us.

"Can you guys please keep it down? I'm trying to sleep!"

Oh crap, she's awake! Wait, which one is that?

Yotsuba grinned sheepishly up at her sister. "Ah, sorry Nino. We'll lower the volume."

"Good!"

Then, she was gone.

We returned to our studying, and Miku returned to her tea, now studiously avoiding eye contact with me.

...I think I may have just blown my relationship with another Nakano sister. Fantastic. Exactly what the doctor ordered. This is what I get for being nosy. Mind your own business, Fuutarou.

I sighed miserably.

Well, there's nothing I can do about it now. Guess we'll need to expand Operation Twintail.

About thirty minutes later, a door on the second floor opened and shut again, and then Nino came down the stairs. Unlike Miku, she was actually dressed, instead of remaining in her pyjamas. With her bows now firmly in place, I was able to recognize her at first glance.

They really are identical, huh? I'm really glad Yotsuba wears that garish ribbon all the time, it makes it easy to pick her out.

"Eh? Nino, I thought you were trying to sleep?" Yotsuba asked, worriedly. "Were we still too loud?"

"No, I just couldn't fall back asleep," Nino huffed. "The damage was already done. I'm going to make breakfast. Do you guys want some?"

"Yes please," Miku said. "I've had enough pretzels already for the day."

"Pretzels...?"

Nino looked over at the coffee table, and then sighed.

"You're having that much junk food this early in the morning? Seriously, Yotsuba?"

"Hey! This is my fantastic spread! I worked super hard on it!"

"Right. Did you have any actual food yet, or was it just fantastic spread?"

"...Just fantastic spread."

"I'm going to make food. You're going to eat it."

Yotsuba pouted. "Fine."

I reached over the table and patted her on the shoulder. "Don't worry, there's still loads of time to eat your fantastic spread. We have all day."

Nino eyed me up. "I guess I'll make some for you too, Mr. Nerd. I'm not going to abandon Yotsuba's guest, no matter how I feel about them."

I bowed my head. "My deepest appreciations."

Nino raised an eyebrow at me. "I can't tell if you're making fun of me, or if you're just weird."

"Weird," Yotsuba said, grinning. "Definitely weird."

I shot her a look. "You've been holding that in for the last hour and a half, waiting to get revenge, haven't you?"

"Guilty as charged, Uesugi-san!"

Nino scowled at me, but didn't say anything else, and just walked over to the kitchen. A few minutes later, the sound of oil on a hot skillet filled the apartment, and the aromatic smell of onion and garlic permeated the room.

"Ahh, that smells amazing," Yotsuba said, a blissful look on her face.

"Of course it does," Nino said from the kitchen with a slight smirk. "I'm the one cooking it."

Then, she put a lid over the skillet, and walked over to the couches.

"Yotsuba, can you go up and see if Ichika and Itsuki want any?"

"Oh, Ichika isn't here, she left super early this morning," Yotsuba said, getting up. "She said that her work wanted her for the full day."

Nino frowned. "What even is that part-time job of hers? Imagine wanting a high-schooler that early in the morning on a weekend..."

Yotsuba shrugged. "Beats me. We should ask her about it sometime."

She then made her way up the stairs, and Nino returned to the kitchen. A few minutes later, Yotsuba came back down, a sad look on her face.

"She doesn't want any."

Nino stared at her in shock. "Wait, Itsuki doesn't want breakfast? Are you sure that's her in there?"

"Yeah. She says that she doesn't want to see Uesugi-san, and so she's going to stay in her room."

Well, she was right about one of them hiding...

Nino rolled her eyes. "He's a jerk, but he's not worth missing breakfast over. Fine, we'll just send a plate up to her."

I'm right here, you know! I can hear what you're saying!

I managed to keep my mouth shut (a truly herculean feat), and just went back to my studying. A few minutes later, Nino carried four plates over to the table near the stairs, and called us over. I put my textbooks down, and meekly went to eat the food made by the girl who hated me.

For food made by someone who hated my guts, it was phenomenal. It was cooking like this that made me realize that, for all of her talents, Raiha was still just a grade-schooler. This was cooking. As I ate the beautifully crafted omelet that Nino had made, I could tell that I was only appreciating a small fraction of its worth.

Curse my poor-man's palette! Curse it!

Yotsuba carried a fifth plate up the stairs to Itsuki's door, and when she came down again, the plate was gone, so I could only assume that the recluse had accepted the offering. The sisters chatted away with one another, but I silently stared up at the small bit of Itsuki's door that I could see from my spot.

I don't think I've ever had someone hate me so much that they tried to forgo food before. That's gotta be a first. A new low for Uesugi Fuutarou.

After we finished breakfast, I bowed my head to Nino. "Thanks for the food. It was delicious."

She rolled her eyes at me. "I don't need the dramatic gratitude," she said, and then cleared the plates away, and began washing them. I turned to Yotsuba and shrugged helplessly, my sincerity rejected. She shrugged back, and then we returned to the couches to study.

"Should we finish up with social studies?" I asked Yotsuba. She shook her head.

"Nah, I've completely lost my train of thought with it. Let's just move on, and come back to it later."

I nodded. "Alright, sounds good. What was the next subject on the list?"

Yotsuba grimaced. "My one true enemy."

"Ah. Math."

Yotsuba sat on the floor again, and took out her math textbook. She stared at it, and then just seemed to melt, ending up hunched over the book.

"Beeeeh. I don't like math."

"Do your best, Private Yotsuba. You can't let such trifles stop you."

In the kitchen, Nino rolled her eyes, but I ignored her. This girl seems to be deriving great pleasure from mocking every single thing I do, or taking offense at it. I'm not sure I believe that she'll come around on her own.

Yotsuba perked up at my encouragement, and saluted.

"Aye, you're right! Such hardships can't stop me -- I've got a promotion to earn!"

She then gave me a wink and a cheeky grin, holding up her hand with her thumb and middle finger forming a circle. "Gotta win that sweet, sweet promotion cash."

I gave her a blank stare. "Wait, you're getting paid? Huh. Our accountant has a lot to answer for."

"Waaah! Slavery! This is slavery! I demand a fair wage!"

We both laughed, and then got back to work. As we did so, Miku abandoned us to go back up to her room, and returned about ten minutes later fully dressed, her signature headphones draped around her neck. She plopped down on the couch in her previous spot, and pulled out her phone, presumably to listen to music. I idly noticed that she'd left as soon as we decided to move on from Sengoku warlords.

Maybe my guess wasn't as far off as she led me to believe. I'm not an idiot though, I'm not going to press the point. Don't want to dig myself into any deeper of a hole.

The next hour and forty-five minutes was spent alternating between solving problems myself, and diligently attempting to teach Yotsuba the bare basics of trigonometry -- in particular, Pythagoras' theorem, which wasn't even really trigonometry. As much as I wanted to jump ahead to covering the current class topic, trigonometric identities, there was no way she was going to get to that point any time soon.

What has she been doing up until now...?

After she finished cleaning the dishes, Nino went over to the bookshelf, and pulled what appeared to be fashion magazines off the lowest shelf. She then sat at the table, and poured over them, really appearing to drink in every detail of every page.

I can't tell if she's genuinely that fascinated by fashion, or if she's just trying to distract herself from the irritation of my existence.

I felt a brief twinge of annoyance at that thought, but Yotsuba's complaining about Pythagoras distracted me from it.

At about the forty-five minute mark of the math section, the sound of a door opening emanated from the second floor, and I glanced up to see Itsuki coming down the stairs. She studiously avoided making eye-contact with me, and went into the washroom. A few minutes later, she emerged, and returned to her room without saying a single word.

"Yikes, cold." Yotsuba whispered to me, leaning in and shivering. "Good luck with that, Uesugi-san."

I raised an eyebrow at her. "This was your idea, you know."

"I'm just trying to be supportive!"

"Well, thanks. I'm going to need it."

She grinned, and lightly slapped a hand on my shoulder. "I've gotcha, pal!"

Around the time that the alarm was set to go off to finish the math section, Nino seemed to get bored with the magazines, and eventually she wandered back into the kitchen.

"I'm making lunch," she announced to no one in particular.

"Eh? We just ate!" Yotsuba complained. "Also, I'm filled up on fantastic spread."

"That was two hours ago, it's lunch time. Also, I'm bored."

I raised my hand. "I'll have some, please."

Yotsuba looked at me in shock. "Betrayal! Tell me, was my fantastic spread not good enough for you, Uesugi-san?"

I shook my head. "It's not like that. I'm just hungry for food, and not snacks."

Nino stared down at me, a vaguely scornful expression on her face.

"I'm not cooking for just you. Hey, Miku! Do you want lunch?"

Miku didn't respond, her headphones over her ears. She seemed to be rocking back and forth to a sort of rhythmic beat. Nino frowned, and then walked over to her, and pulled her headphones off.

"Hey! Nino, give those back!"

She scowled down at her younger sister. "I was trying to talk to you, Miku."

"Give them back!"

Nino dropped the headphones in Miku's lap. "I asked if you wanted lunch. I'm bored, I want to cook."

Miku pouted, and put the headphones back around her neck.

"What are you gonna make?"

"I dunno yet. I'll decide once I know who's eating."

"I guess I'll have some. Not too much though."

Nino nodded, and then walked up the stairs, presumably to talk to Itsuki. When she came back down, she was scowling.

"She's not coming down for lunch either. She still wants a plate though. That meat-bun monster is being real disrespectful!"

I felt a pang of guilt. While I certainly wanted to make it so Itsuki didn't hate my guts, if only for Yotsuba's sake, I also didn't particularly like the idea of being a source of intra-familial strife, which my presence was clearly causing. As Nino grumpily made her way into the kitchen, I silently continued with my math studies, hoping that the endless cotangents and cosecants would distract me from my sin.

"Hey, Uesugi-san. I think I've figured out Pythagoras' theorem. I don't really know why it works though..."

A distraction. Excellent. Thank you, Private Yotsuba!

I walked around the table to sit next to her.

"Here's this nice proof I found in a reference book. Let's use the example of a triangle with side lengths of three, four, and five. If you're squaring something, that's basically the same as thinking about a square with a side length equal to that number -- that's why it's called squaring. So if we think about squares with a side length of three, four, and five, we can draw them like this."

I drew squares with nine, sixteen, and twenty-five smaller squares inside respectively.

"Now, suppose you take the smallest block, and add all of its interior blocks to the middle block -- how many blocks do you get?"

"Uhh.... Oh! You get twenty-five!"

"Which is the same as five squared, right?"

"Right!"

"So that's why it works. It basically says that if you attach a square to each part of a right-angle triangle, and you add the two smallest squares together, you get the biggest square. That's the whole theorem."

"Wow, Uesugi-san! That's a genius for you!"

From the kitchen, Nino muttered, "Friggin' nerd."

Wow. Ichika wasn't kidding about the effects of emotional whiplash yesterday. I have no idea how to feel right now.

About fifteen minutes later, Nino finished making lunch, and we went to eat again. Yotsuba wasn't hungry, but came and sat at the table anyways -- as I ate the cheese and ham sandwich that Nino had made for myself and Miku, she pouted and stared at me.

"What is it?" I asked her after swallowing a bite.

"I feel like my fantastic spread isn't getting the love and appreciation it deserves," she complained.

"Yotsuba, my culinary world has already been blown open by those dips today. Don't feel bad about it. Besides, snacks aren't lunch, they're snacks. They're the backdrop to the entire day."

Yotsuba huffed, but seemed to brighten up after that.

As we finished up, I was about to go back to studying, but then I felt a soft tug on my shirt. I turned around to see that Miku had pulled me back.

"Miku?"

"Fuutarou, can I talk to you for a minute?"

"Uh... sure. What's up?"

"Not here. Can you come out onto the balcony?"

I glanced back at Yotsuba, and she gave me a thumbs up, before settling back into her seat on the floor.

"I'm gonna eat all the tortilla chips while you're gone, so you two go on ahead -- all the more for me!"

Hey! I barely had any yet!

Grumbling to myself, I followed Miku out onto the balcony. She closed the door behind us, and then walked over to the railing, and stared out into the distance. I followed her, and was shocked by the blast of wind that swept over me.

It's friggin' cold. Yotsuba wasn't kidding about waiting to come out here. What the hell could she possibly want to talk about?

Miku turned back around, and seemed to be looking past me into the apartment. I turned around as well, and saw that Nino was doing dishes, and Yotsuba was munching on snacks.

Is she... checking that they're not within earshot?

"I need to apologize to you, Fuutarou."

...Eh?

"I panicked, and lied to you this morning. I'm really sorry."

I turned back around to face her.

"That's... fine? Wait, are you talking about the thing with the warlords?"

Glumly, Miku nodded. "You just asked me out of the blue like that, and I panicked. I didn't want Yotsuba to hear, and I wasn't sure if my other sisters were awake, so I just decided to lie about it. But it's been eating at me ever since then, and I just needed to get it off my chest."

"Wait, so you do like Sengoku warlords. Why do you want to hide that from your sisters?"

Miku glanced to the side. "They talk about love and hot guys all the time, and I like bald middle-aged men from four-hundred years ago. Isn't that weird? It's embarrassing."

I... somehow can't envision Yotsuba talking about hot guys.

I shrugged. "You're talking to a guy who's passion in life is studying. I don't think being interested in history is a particularly embarrassing hobby. It's ok to be proud of what you like."

Miku smiled slightly as I said this, then shook her head.

"Regardless, please don't tell my sisters."

I sighed. "If that's what you want, I'll keep my mouth shut, but I don't really understand."

"Thank you."

"You could have joined us when we were studying about them though, you know? I'm sure you know a lot more than the bare-bones coverage that's in the course material."

She stared at me with sad eyes. "I couldn't do that. Yotsuba would have found out."

I shrugged. "Fair enough, I guess. Anyways, thank you for trusting me enough to confide in me."

Miku seemed a bit taken aback by that, but then just nodded.

"Shall we go back inside?" I ventured. "It's freezing out here."

She nodded again, and we both made our way back inside the apartment. Miku and I sat back down on the couches, and Yotsuba looked back and forth between us from the floor, her mouth full of tortilla chips.

"So," she said, swallowing the chips. "What was that about?"

"It's. A. Secret." I retorted, smirking slightly.

"Hey, that was my line! You scoundrel!" Yotsuba pouted.

"It's not your line, Yotsuba, that's in like every slice-of-life anime," Miku said, putting her headphones back on.

"Meanie," Yotsuba said back, her pout deepening.

"Anyways, I think that's probably enough math for today. Next on the docket was science, right?"

"Yep. I think we were doing biology?"

Yotsuba and I continued our hard work, though our pace was frequently broken by snack breaks. I felt somewhat obligated to partake more than I normally would, given the level of effort Yotsuba had clearly put into the spread. By the time the alarm on her phone next went off an hour and a half later, our snack supplies were starting to run seriously low. It also didn't help that Miku was also partaking of the spread.

Speaking of Nino, she had briefly returned to her room after making lunch, and had returned to the table with nail polish. As we studied, she painted her nails an alternating pink and blue pattern, and as they dried, she watched videos on her phone. Around the time the alarm went off, she was in the middle of painting small butterfly designs on the dried nails, and jumped slightly as the phone rang.

"Argh, Yotsuba! I screwed up because of that! It's so loud!"

"Ah, sorry Nino. My bad! I had it turned up because I thought I'd be too distracted to notice it otherwise!"

She sighed. "It's fine, I can fix it. It's not your fault."

Nino then returned to doing art on her nails, her focus entirely too preoccupied to notice anything else -- which was good, because any time that she was spending preoccupied was time that she wasn't spending mocking me.

"Final subject is English," I said, pulling out my textbook. On the other couch, I saw Miku look up, see my book, and scooch further away from the table -- or at least as far as she could, given that involved her backing up straight into the couch.

I guess... she really doesn't like English?

About ten minutes into our studying, Yotsuba glanced at the clock on the wall.

"Hey, Uesugi-san, it's around mid-afternoon now, but we've still got all of our English to do, and also we need to finish off the social studies section. Do you want to stay for dinner?"

At the table, I saw Nino stiffen, and then turn to look at Yotsuba with an annoyed look on her face.

"I'm making dinner for this jerk as well as everyone else?"

"I can cook instead if you want, Nino!"

"...Nevermind, I'll do it," Nino grumbled, turning back around.

Yotsuba smiled sheepishly. "I guess my cooking isn't too great..."

"Still better than mine," Miku said glumly.

"Is that so?" I said, not really paying attention. "I'm sure your cooking is fine."

I then glanced up at Yotsuba. "Sure, I'll stay. Let me just text Raiha and let her know I won't be home for dinner."

"Who's Raiha?" Miku asked.

"His kid sister," Yotsuba answered as I pulled out my phone and began composing my email. "I bet she's pretty cute!"

"She's adorable," I replied absent-mindedly as I wrote. "Cutest elementary schooler in the world."

"Ahhh, I wanna meet her," Yotsuba said wistfully, stretching out her arms on the table. "I bet we'd get along great."

"Also, she's a smart cookie. She does all the budgeting and cooking in the house."

"Eh?!" Yotsuba said, shocked. "That's one clever grade schooler!"

"Right?"

I fired off my email, and then put my phone away.

"Alright," I said, cracking my fingers. "Let's power through this."

I wasn't entirely sure that I was just talking about studying.