Jinshi was removing the coffee maker's water tank when Mao Mao was reading a book. A corner seat in the student council room. She'd been entrusted with Koshi Festival prep documents under the guise of "organizing" them, but they'd been sorted long ago. Mao Mao wondered vaguely how many days it had been since Monday. Monday was document organization. Tuesday was tea refills. Wednesday was rewriting the whiteboard because the handwriting was messy. The reason changed every time. Mao Mao kept her eyes on the book in her hands, dimly aware of the secretary writing something in her notebook. She couldn't read it, but it was probably something like "the president's reason for calling her changed again." "[serious]…Mao Mao," She looked up from her book. Jinshi was holding the coffee maker's water tank, his brow furrowed. The coffee maker was something he'd brought with his own money. Inside the tank, something whitish was clinging to the surface. "[serious]This looks dirty," "[serious]It's limescale," Mao Mao closed her book and stood up. She moved beside Jinshi and took the tank from him. She ran her finger along the inside. It was rough. "[serious]Calcium deposits. Minerals in tap water leave residue when they dry. You can remove it in ten minutes with kitchen vinegar and baking soda," Jinshi paused for a moment. "[sarcastic]…You really do know everything," It wasn't a question. It sounded more like a stray thought. "[serious]There are plenty of things I don't know," "[sarcastic]Like what," "[serious]How love works, for instance," Silence. The secretary wrote something else in her notebook. The tips of Jinshi's ears were faintly red. Mao Mao didn't notice. She borrowed vinegar from Tomi at the school store and brought baking soda from the chemistry prep room in the east building. She washed the tank, poured in the vinegar and waited five minutes, added the baking soda to make it fizz, then rinsed it. The steps were simple. The tank returned to its original transparency. Jinshi stared at the gleaming tank for a while, just watching it. "[gentle]…Amazing," His voice was quiet. The kind of volume meant for no one but himself. Mao Mao felt that single word catch in a corner of her chest as she dried her hands. She didn't understand why it caught. "Amazing" was an evaluation of the technique, not of her as a person. Just a fact. And yet, somehow, it didn't feel bad. Even though she'd thought he was a troublesome person. Mao Mao set that strange feeling aside for now and went back to her seat to get her book. ──── After school, she headed to Chemistry Lab B in the east building. Today she planned to analyze the components of dried chamomile she'd brought. As she walked down the hallway, mentally arranging which column to use, she opened the lab door. The usual smell. A mix of chemicals and dust. She set the chamomile bag on the work table and reached toward the shelf. Her hand stopped as she was about to grab a flask. Something was wrong. Mao Mao remained still and used her nose again. From the back of the shelf, there was a pungent odor. Faint, but definitely there. It wasn't coming from the flask—it was coming from a bottle behind it. She slowly withdrew her hand. She confirmed the bottle with her eyes. The label read "Saline Solution NaCl 0.9%." Saline solution had no pungent odor. Mao Mao brought her nose close to the bottle without opening the cap and inhaled once. (Nitric acid.) The volatility and the type of pungent odor. There was no mistaking it. And the concentration wasn't low. Around sixty percent. She peeled off the label. Her fingertips trembled slightly. It wasn't fear. She was just thinking about what this meant. From under the label, the original seal appeared. "HNO₃ 60%." It was an intentional relabeling. If she hadn't noticed—if she'd poured it into a flask—it would have gotten on her hands, her face. Sixty percent nitric acid on skin would cause tissue necrosis. This wasn't something to laugh off. Mao Mao put the peeled label in a ziplock bag and stored it in her bag. She turned off the lab lights, closed the door, and stepped into the hallway. Her feet naturally turned toward the student council room. ──── Jinshi was still there. The moment he looked up from his computer and saw Mao Mao's face as she opened the door, he seemed to sense something. "[surprised]What's wrong," "[serious]I found a reagent bottle in the east building lab with a relabeled sticker," Mao Mao stated only the facts, in order. That a saline solution label had been placed on a nitric acid bottle. That she'd noticed by smell. That she'd confirmed without opening the cap. That she'd preserved the label as evidence. Jinshi listened silently. After she finished, he said nothing for about five seconds. "[cold]…If you'd used it without knowing," He stopped mid-sentence. His voice carried something it usually didn't. Urgency, maybe. Fear. "[serious]I noticed the smell before using it, so it's fine," Mao Mao answered that way. She analyzed that Jinshi's pale face was because he felt responsible for facility management as student council president. She couldn't think of any other possibility. "[cold]I'll check the entry and exit records. Come," ──── The east building had a paper logbook. The two of them sat side by side at the long table in the student council room and spread out the logbook. Mao Mao traced the dates and names in the logbook with her finger as she read. Confirming the date, confirming the time, confirming the name. The distance between Jinshi's shoulder and her own was less than five centimeters. Mao Mao didn't particularly think anything about it. It was easier to read the logbook from up close. It was practical. Meanwhile, Jinshi was reading the same line in the logbook for the third time already. The numbers wouldn't stick in his head. Every time Mao Mao traced the logbook with her finger, that fingertip entered the edge of his vision. He knew he shouldn't look, but his gaze kept trying to drift that way. (Focus.) Jinshi read the line a fourth time. Mao Mao remained completely unresponsive, continuing to move her finger across the logbook. "[serious]Is there no security camera here because the installation proposal never came up," "[cold]…I opposed it," Mao Mao looked up. "[cold]Monitoring students around the clock felt wrong. There's the privacy issue too. So I voted it down," "[serious]Then regarding this incident, that was a judgment error on your part as president," The response came without hesitation. Jinshi laughed bitterly. His laugh was slightly different from his usual composed one. "[cold]…Yeah," He said only that and returned his gaze to the logbook. But his hand had stopped moving. "[cold]Things I think are right and do—I rarely get anyone's approval for them," The words came out in fragments. Almost like thinking aloud. "[cold]I was elected with 87 percent of the vote, but there's not a single person I can be honest with. Everyone talks to me as the 'president.' I function better alone, so that's how it is. That's all there is to it," After he finished speaking, Jinshi himself seemed slightly surprised and closed his mouth. This was the first time he'd ever said something like this to anyone. He didn't even understand why he was saying it now, here. Mao Mao didn't look up from the logbook. She didn't stop moving her finger. After a while, she spoke quietly. "[serious]Even with lots of people around, some people can still be lonely," There was no sympathy or comfort in it. Just observation. Something stopped in Jinshi's chest. The sensation of having a part of himself that no one could see pinpointed exactly. Not comfort. Not pity. Just—being seen. Confirmation of that. Jinshi said nothing. He stared at the logbook and breathed quietly. ──── After checking the entire logbook, the only entry records for the lab were the chemistry club president Fujita (previous day) and Mao Mao (same day). "[serious]Should we talk to Fujita," "[cold]We should probably. He's suspicious, at least," "[serious]That person rejected my application to join the club. He has motive, but no evidence. If we go ask him now, he'll just be on guard," Jinshi stopped. "[surprised]…You rejected his application," "[serious]I told him the club fees were wasteful," "[sarcastic]Yeah, that'd piss anyone off," Jinshi pressed his forehead. After a moment, when the question "so what do we do now" hung between them, both turned in the same direction. "[serious]If the culprit has relabeled other reagent bottles, checking the entire shelf will show the scope of the damage. If the same method is used elsewhere, the target is probably not me personally—they're likely aiming to cause chaos in the lab," Jinshi paused for a moment, then looked at Mao Mao. "[cold]…You're smarter than me," "[serious]That's right," Not a second of hesitation. Jinshi laughed. This time it was a genuine laugh. "[laughing]You're too honest," Mao Mao didn't quite understand why Jinshi was laughing, but somehow it didn't feel bad. ──── The next morning, the two of them entered Chemistry Lab B in the east building and began checking the chemical shelf from end to end. Bottle by bottle, they cross-referenced the labels with the contents. Mao Mao confirmed by smell, and Jinshi made checkmarks in the logbook. When they reached the third shelf, Mao Mao's hand stopped. A bottle with an ethanol label. She smelled it. "[serious]…It's acetone," Jinshi stopped his pen. "[cold]Another one," "[serious]Ethanol and acetone have similar smells, so it's easy to miss. But acetone is highly flammable. If there's an open flame during an experiment, it's dangerous," Not just one. Multiple. Mao Mao looked across the shelf and opened her mouth. "[serious]This isn't random mischief. Someone is deliberately targeting a specific person," Jinshi's expression tightened. The two of them left the lab and walked down the hallway toward the main building. Through the hallway windows, they could see classmates in the courtyard making decorations for the Koshi Festival. Colorful poster board. Cheerful voices carried through the window glass. Mao Mao gazed vaguely at the scene, and something she'd remembered came to her lips. "[serious]Did you oil the lock on the student council archive," "[cold]Not yet," "[serious]You should do it soon. That lock was rattling," Jinshi answered "got it" a moment later. Watching Mao Mao's back, he felt a vague reluctance to let her leave like this. The reason wouldn't form into words. Just—somehow. "[cold]Come again tomorrow," Mao Mao didn't turn around. "What's the reason," she asked. Jinshi thought for a moment before answering. "[cold]The shelf check isn't finished," "[serious]That's true," Mao Mao continued down the hallway. Jinshi watched her back and, for the first time that day, found himself remembering the moment he'd laughed. The shelf still had sections left to check. The culprit's identity remained unknown.