Yesterday, the shelf inventory still hadn't been finished. There was no guarantee Mao Mao could complete it today, she thought while pedaling her bicycle. The eastern sky was beginning to brighten. She passed the bus stop in front of Koushi Academy and went through the school gates. It was before morning homeroom started. When she passed in front of the student council room, she heard Jinshi's voice from down the hall. "[surprised]……there isn't any" A voice calling for the secretary. Mao Mao stopped. "[serious]It's all gone" The door opened. The secretary came out with a pale face. Seeing Mao Mao, she said "Oh, Mao Mao." That alone told her most of what had happened. The contents of the archive had disappeared. Budget approval forms, event permits for participating organizations, copies of contracts with external vendors—every single document related to the Koushi Festival. Not a single sheet remained. Jinshi stood in front of the archive, staring at the empty shelf. Long jet-black hair, deep crimson eyes. He usually stood with an air of composure, but today was different. She couldn't put her finger on what was different, but Mao Mao felt it. "[serious]What about the archive lock?" Jinshi turned around. "[serious]No damage. No signs of forced entry" "[serious]I see" The homeroom chime rang. The two of them headed to class. ──── By lunch break, a post had gone up on the school's internal SNS. The girl sitting next to her turned her screen toward Mao Mao. "Mao Mao, did you see?" Mao Mao didn't own a smartphone. While almost every student had been looking at it since morning, she alone was behind. One photograph. A nighttime hallway. In front of the student council room's archive, Jinshi stood holding a key. From the angle, it had been taken from the side of the hallway wall. The caption read: "Jinshi sneaks into the archive alone at midnight, embezzles documents?" "[whispers]I knew it. People who are too perfect always have something to hide" "[whispers]I should've stayed away……" The girls who had been talking about Jinshi until yesterday switched directions in an instant. People's fickleness was fast. Mao Mao listened to the conversation in silence and looked at the photo again. The direction of light from the window. The angle of the shadows. The color of the fluorescent lights reflected in the hallway glass. "[serious]Around 7:30 PM" "Huh?" "[serious]From the direction and length of the shadows. It was overtime" There was a moment of silence. Then a wave of voices rose. If there was a word for "completely backfired," the classroom right now was close to it. Mao Mao didn't fully understand why it had backfired, but she took out her lunch box anyway. ──── After school, when she headed to the student council room, an unfamiliar person was standing in front of the door. Medium-length hair pure white. Calm eyes. The right eye was blue, the left eye silver—odd eyes with different colors. About 175 centimeters tall. Slightly shorter than Jinshi. There was a strange quietness about him, the kind that gave the impression of "always thinking about something" just by standing there. "Mao Mao?" The person smiled when he saw Mao Mao. Whether it was a calculated smile or a natural one couldn't be determined in just one second of looking. "[cold]I'm Rihaku. Jinshi's classmate since middle school. Vice president" The student council room door opened, and Jinshi came out. "[surprised]Rihaku" "[cold]I contacted you but got no response, so I came. What happened?" "[serious]……The documents disappeared" "I saw. The SNS too." Rihaku said flatly. "[cold]I'll investigate. Jinshi, you do nothing" On the surface, it looked like perfect reinforcement. Jinshi paused for a moment before saying briefly, "Rihaku……thanks." Rihaku looked around the room. His gaze stopped for a moment on Mao Mao. It stopped, then moved again. A casual confirmation, but a definite one. "[cold]So you're the girl Jinshi's been looking out for?" As he approached Mao Mao, Rihaku smiled meaningfully. "[cold]I'm curious too" Mao Mao observed Rihaku's face head-on for one second. Bone structure. The degree of left-right symmetry. The shape of the irises in his odd eyes. "[serious]Jinshi's bone structure is superior" Rihaku froze. Completely froze. His mouth hung half-open, searching for the next words. Mao Mao didn't exactly understand what was happening. She had just stated a fact. Jinshi was 182 centimeters, closer to the golden ratio of facial proportions. Anyone could see that if they observed carefully. When she looked at Jinshi, he had the face of someone who wanted to laugh but couldn't. She didn't understand why he'd make that face either. ──── The three of them sat side by side at a long table. The student council room. The large ginkgo tree outside the window. The coffee maker. "[serious]I'll check the archive structure" Mao Mao stood in front of the archive and confirmed the double lock. A padlock and the keyhole on the doorknob. The scratch marks she'd seen the last time she was here were still there. "[serious]Only three people have keys to this archive: the president, vice president, and advisor" That was all she said. She didn't say what came next. Even without saying it, the gazes in the room naturally shifted. Toward Rihaku. Rihaku's smile became slightly rigid. "[serious]……Are you suspecting me?" His voice lowered. The previously calm way of speaking now had a thorn in it for the first time. "[cold]Calm down, Rihaku. Mao Mao was just stating facts" "[serious]If you state facts, the culprit gets narrowed down. That means for me——" "[cold]I know. But this isn't the time to get emotional" Silence fell. On the long table, there was a stack of documents no one touched. Only the coffee maker's warming lamp glowed red. Mao Mao took her gaze away from the keyhole and spoke quietly. "[serious]When does Advisor Kataoka come to school?" The practical single question moved the frozen air slightly. Jinshi answered, "Twice a week, Wednesdays and Fridays." The tension eased slightly from Rihaku's shoulders. Someone was the culprit, someone was innocent, and there was still no basis for making that judgment. That was all Mao Mao was thinking about. She had no intention of blaming Rihaku or defending him. Just that there were three keys. Jinshi looked at Mao Mao's profile. From the moment Rihaku stood beside Mao Mao, something had been stirring in his chest. Something was stirring, but he had no idea what it was. It wasn't exactly unpleasant. Just unsettling. (Why?) Jinshi pressed the center of his chest for a moment. Quickly, at a time when no one was watching. ──── That night, a message arrived for Mao Mao through the secretary. There was no subject line. It just said "There's a new post on SNS." Mao Mao borrowed the smartphone of the woman next door to check (this was the third time today. It was getting awkward). The new post had a video attached. Footage shot through the hallway glass. Jinshi's back as he operated the archive. The text read: "Evidence footage: Jinshi hiding documents." The next morning, the first thing Mao Mao did when she arrived at school wasn't to rewatch the video. She went to the student council room and stared at the lock from the front. The side of the padlock. The edge of the keyhole on the doorknob. Jinshi arrived. "[serious]……The scratches on the lock are two different types" "Huh?" "[serious]Scratches from the original key, and slightly shallower scratches. There are marks from a duplicate key being used" Jinshi moved closer to the lock. He looked at the place Mao Mao's finger was indicating. Indeed—if you looked closely, the depth of the scratches was subtly different. "[surprised]……When did you check this?" "[serious]The first time I came here. I'd been wondering about it since the time before last" "[surprised]The time before last, what——" Jinshi held his head. Mao Mao didn't quite understand what he was confused about. She'd been wondering, so she checked. That was all. But now. Evidence that someone had duplicated the key had appeared for the first time. The possibility that the culprit wasn't the president, vice president, or advisor had surfaced for the first time. Jinshi muttered quietly while looking at the lock. "[cold]……Someone made a duplicate. When? How?" "[serious]I don't know. Not yet" She put slight weight on the words "not yet." Not knowing and not having found out yet were different things. ──── After school. The secretary and treasurer came to the student council room together. Both of them looked tense. The secretary spoke first. "[serious]President, tell us the truth" Jinshi's expression didn't change. He didn't let it. "[cold]I didn't do it" "But the evidence——" "[cold]There are marks from a duplicate key on the lock. The culprit is a third party" "That evidence is what Mao Mao said, right?" "……Yeah" "And Mao Mao just transferred here last week" The two of them said "Excuse us" without meeting Jinshi's eyes and left. The door closed. The coffee maker's warming lamp glowed red. Rihaku stood up. "[cold]I'll move from outside. It might be faster to gather information outside the school" Jinshi said nothing. Rihaku looked at Mao Mao for a moment, then left. Two people remained in the room. Jinshi stood in front of the coffee maker and set up a cup. One serving. Coffee dripped. The large ginkgo tree outside the window swayed quietly in the evening light. That back——somehow looked a little smaller. Smaller than it had been the first time she came to this room in the second episode, the back of that student council president. Mao Mao picked up her bag. She stood up. She walked toward the door. When her hand reached the doorknob, her feet stopped. (Why did they stop?) She didn't know. There was no logical reason. She should go home. She'd already noted what she'd learned today. She'd thought about tomorrow's approach. She needed to check on the drying condition of the medicinal herbs when she got home. Yet her feet wouldn't move. Mao Mao took one half-step back and sat down again in the chair by the wall. "[serious]Wouldn't it be more efficient to brew another cup? You're using the same amount of electricity for two cups anyway" Jinshi turned around. Mao Mao's bag was still on the desk. A few seconds passed. Then Jinshi took a second cup from the shelf. "[cold]……Yeah" Two cups of coffee sat side by side, steam rising. Jinshi placed one in front of Mao Mao. The two of them looked out at the large ginkgo tree. Without saying anything. It felt like they didn't need to say anything. The ginkgo leaves rustled in the evening breeze, making a soft sound. The light gradually faded. Something nameless fell like a single grain into Mao Mao's chest. She didn't know what it was. She tried to analyze it pharmacologically, but couldn't identify the components. It was probably the first time she'd felt something like this. There was someone who used a duplicate key. The documents still hadn't been found. The culprit's motive and identity remained unknown. Among teammates who no longer believed in Jinshi, not a single mystery had been solved. But right now, in this moment, the ginkgo tree was swaying, and the coffee was warm—and for Mao Mao, that was enough. Why, she still didn't know.