Morning sunlight streamed through the windows of Class 2-B, but I barely noticed it. My face was buried in hastily borrowed math notes, trying to cram an entire chapter on differential calculus into my brain before first period.
"The derivative of sine is cosine, the derivative of cosine is negative sine, the derivative of—why are there so many trigonometric functions?" I muttered, my silver hair falling messily over my face as I hunched over the desk.
"Your eye bags are impressive," Yuki observed, sitting down at her desk next to mine. "Did you sleep at all?"
"Sleep is for people who remember their math tests," I growled, not looking up. "This is all your fault, you know. You could have reminded me earlier."
"I reminded you three times last week."
"Well, remind me four times next time!"
"Shirogane," Yuki said calmly, pulling my notes away. "You're holding the paper upside down."
I blinked. She was right. "I'm doomed."
"No, you're sleep-deprived and panicking." She placed a canned coffee on my desk. "Drink this and breathe. You're good at math when you're not having an existential crisis over it."
"I spent all night studying," I whimpered, clutching the coffee like a lifeline. "But every time I thought I understood something, three more concepts I didn't know popped up. It's like a mathematical hydra."
From somewhere behind us, I heard Segawa's voice: "Just as Admiral Yi faced overwhelming odds at the Battle of Myeongnyang—"
"Not now, Segawa!" I snapped, making him retreat quickly back to his seat.
Yuki sighed, pulling out a neat stack of flash cards. "Here. I made these while studying. They're color-coded by concept and arranged in order of complexity."
I stared at her. "You're actually a saint disguised as an Ice Queen, aren't you?"
"I just don't want to hear you complain about failing for the next month." She started sorting the cards. "Now, let's go through the basic derivatives first. You have..." she checked the clock, "twenty minutes before Kobayashi-sensei arrives."
"Twenty minutes to learn calculus. No pressure." I took a long drink of coffee. "Why didn't I pay attention in class?"
"Because you were too busy reading manga under your textbook?"
"That was rhetorical, Yuki."
She smiled slightly, holding up the first card. "Derivative of x squared?"
"Two x?"
"Good. See? You know this. Derivative of e to the x?"
"...e to the x?"
"Perfect. Natural exponential function is its own derivative. Now—"
The classroom door slid open, and my heart stopped until I realized it was just another student. Yuki put a steadying hand on my arm.
"Rei," she said quietly, using my given name. "You're going to be fine. You're smarter than you give yourself credit for, even if you are terrible at time management."
"Time's up. Please pass your papers forward," Kobayashi-sensei announced, his monotone voice somehow making the words sound even more final.
I slumped forward onto my desk as my test paper was collected, letting my forehead rest against the cool surface. Around me, I could hear the usual post-test cacophony of sighs, groans, and the inevitable "What did you put for question seven?"
"Shirogane," Yuki's voice came from beside me. "Are you still breathing?"
"No," I mumbled into the desk. "I've ascended to a higher plane of existence where derivatives don't exist."
"Did you at least finish all the problems?"
I turned my head slightly, just enough to peek at her with one eye. "Define 'finish.'"
"Shirogane..."
"I wrote something for every question," I defended weakly. "Whether that 'something' made mathematical sense is... debatable."
From somewhere behind us came Segawa's booming voice: "Fear not, noble ally! Just as Admiral Yi turned defeat at Chilcheollyang into ultimate victory at Myeongnyang, you too shall—"
"Segawa-kun," Kobayashi-sensei interrupted, "please save the historical reenactments for after class."
As Kobayashi-sensei walked away with our papers, I finally sat up, my silver hair probably a mess from being pressed against the desk. "I definitely failed that last integration problem. Who even needs to know how to integrate secant?"
"Nobody," Yuki said practically, "but that's not the point. How did you do on the derivative section? We spent most of this morning on that."
"I think..." I paused, trying to remember through my caffeine-addled brain, "I actually remembered the chain rule? Your flash cards helped. Though I might have accidentally written some manga dialogue in the margins during a moment of panic."
"Please tell me you didn't quote 20th Century Boys in a math test."
"...it was Monster, actually."
Yuki pinched the bridge of her nose beneath her glasses. "Well, at least you're consistent in your questionable life choices."
"Says the person who color-coded her flash cards."
"My 'questionable' organization system just saved your grade, didn't it?"
Before I could retort, my phone buzzed with a message. I pulled it out, then immediately groaned.
"What is it?" Yuki asked.
"Akane. She wants us to start Segawa's photography lessons today." I showed her the message. "Apparently, she's 'striking while the iron is hot' or whatever."
"After that math test? Are you sure you're up for it?"
I glanced back at Segawa, who was enthusiastically explaining something about naval formations to his increasingly confused desk mate.
"Maybe it'll be a good distraction," I said. "Besides, how hard can teaching basic photography be?"
Yuki gave me a long look. "You really need to stop tempting fate with questions like that."
The school rooftop had become our unofficial lunch spot ever since Yuki discovered I was eating alone in the stairwell last semester. Despite the "No Entry" sign on the door (which everyone ignored anyway), it offered the perfect combination of fresh air and blessed silence.
"You really should eat more than just bread," Yuki commented, opening her perfectly arranged bento. Each section was organized with the precision of a professional chef – tamagoyaki, rice shaped like rabbits, and vegetables cut into flowers.
I took another bite of my melon pan. "Says the person whose lunch looks like it belongs in a magazine."
"My mom enjoys making them," she said, though I caught the slight flush of pride on her cheeks. "She says cooking helps her relax after dealing with corporate clients all day."
"Must be nice." I leaned back against the fence, watching clouds drift overhead. "All I got this morning was 'Rei, don't forget your keys again' before dad rushed off to another business meeting."
Yuki quietly pushed a portion of her lunch toward me. "Here. Mom always packs extra anyway."
"You don't have to—"
"Just take it. Consider it payment for helping me organize the class library last week."
I accepted the offered tamagoyaki, knowing better than to argue when Yuki used her 'Ice Queen' tone. "Thanks."
We ate in comfortable silence for a while, the distant sounds of other students' lunchtime chaos barely reaching our peaceful hideout.
"So," Yuki said finally, "are you really going to help Segawa with photography?"
"I promised Akane I would." I sighed. "Though I'm starting to regret it. What if he tries to recreate historical naval battles with paper boats in the school fountain?"
"That's... oddly specific."
"I saw him with origami paper during math class."
Yuki tried to hide her smile. "At least he's dedicated."
"That's one word for it." I pulled out my phone, showing her Segawa's latest message – a lengthy discourse on how Admiral Yi would have utilized modern camera technology for naval reconnaissance. "See what I have to deal with?"
"You know," Yuki said thoughtfully, arranging her chopsticks perfectly parallel to her bento box, "you complain about him, but you still read all his messages. You could have just blocked him."
I opened my mouth to protest, then closed it again. She had a point.
"It's okay to admit you actually want to help him," she continued. "It doesn't ruin your carefully cultivated image of apathy."
"I don't have a—" The rooftop door creaked open, cutting me off.
"The honorable Admiral's reincarnation has arrived!" Segawa's voice boomed across the rooftop. "I come seeking wisdom about today's impending photography training!"
I shot Yuki a desperate look. She just smiled serenely, gathering her bento.
"Well," she said, standing up, "I suddenly remembered I need to return a book to the library. Good luck with your... naval photography consultation."
"Traitor," I hissed as she walked past.
"Think of it as karma for all those times you left me alone with the class representative," she whispered back, then louder: "The rooftop is all yours, Admiral."