It was just past eight in the morning when she inserted the key into the mailbox. The first-floor hallway of Corpo Mikage drifted with that particular chill of a winter morning. The elderly cat kept by the landlord Hibikuro Shigeru was curled up on the entrance mat. 雨宮藍子 glanced at it once, then thrust her hand into the mailbox. A brown envelope. The sender's field was blank. It was thick. When she picked it up, she felt the weight of folded papers packed tightly inside. She opened it and pulled out A4 sheets stapled together. Printed tables. Columns and rows, numbers and times, delivery destination codes. Seven Fresh Line delivery records. (Seio-san is too meticulous.) The staples were placed with ruler-like precision. Exactly five millimeters from the top-left corner, at a perfect forty-five-degree angle. The angle of a detective's paperwork habits. As 藍子 turned back down the hallway with the envelope, the sound of someone frantically mashing the intercom buzzed from outside. Ding-dong-ding-dong-ding-dong. The intervals were restless. "[excited]藍子-san!! Are you awake!?" The voice echoed through the hallway. The cat opened one eye in annoyance. 藍子 stepped outside and peered through the gate gap. Mint-green twin tails caught the morning light. Golden eyes sparkled. In her hands was a convenience store bag. "[serious]A package with no sender—it arrived." "Huh?" ミナ pushed open the gate and looked at the brown envelope in 藍子's hands. "[surprised]What's that, no sender...that's scary!! You opened it in the hallway!?" "[serious]It's a method to avoid leaving records. Nothing to fear." "But opening a strange envelope alone at the mailbox—" "It's from Seio-san." "...Huh?" "The angle of the staples matches that person's meticulousness." ミナ froze for a few seconds, processing the answer. Then she whispered, "So you identify people by staple angles..." ＊ When 藍子 opened the door to Corpo Mikage Room 206, the six-mat space felt slightly stale. She hadn't aired it out this morning yet. The reasoning board sprawled before the window. Memo papers, red stickers, and arrows covered the wall, glowing white under the slanting morning light. ミナ entered and looked around the room. It was her third visit. "[gentle]I was going to say you could clean up a little more, but—" ミナ stopped in front of the board. The number of memos had clearly increased since last time. Sticky notes, printouts, handwritten numbers, arrows drawn in red and blue. "...Yeah, I get it. You need this." She said nothing more about cleaning. 藍子 pulled the stack of papers from the brown envelope and sat on the floor in front of the board. Fresh Line account data she'd pulled out last night was spread beside her. ミナ also sat down and rolled out two canned coffees from the convenience store bag. She silently rolled one toward 藍子. "[gentle]Drink. You need caffeine when you're thinking." 藍子 picked up the can and opened it. Bitter. But warm. The cross-referencing began. 藍子 moved her pen. ミナ traced the table with her finger. They barely exchanged words. But the work progressed. The first commonality was confirmed ten minutes later. All seven victims were registered Fresh Line users. "[serious]Next. Residence." The pen ran across the table. Seven addresses concentrated within Mikage Town. All single-person households. ミナ whispered quietly, "...All of them living alone." Her tone was lower than usual. 藍子 continued moving her pen without nodding. Moving to the third cross-reference. Final order time. The ballpoint pen traced through the seven numbers in sequence. 22:47. 22:47. 22:47. 22:47. 22:47. 22:47— 藍子's pen stopped. "[serious]All identical." ミナ leaned closer to the table. "[surprised]Really? Down to the second?" "Down to the minute. All seven at 22:47. The ordering source is Okame, a restaurant on Kagero Street." ミナ looked up. Her golden eyes widened slightly. "Okame... Mifune-san's place?" "Yes." 藍子 wrote large on the center of the reasoning board. "22:47" A single axis connecting all seven cases stood on the board. ミナ stared at the number for a while. Then slowly, she returned her gaze to the table. "[sad]...There are two names here. People I've delivered to before." Her voice had hardened slightly. 藍子 said nothing. She confirmed the two names ミナ was pointing to with her eyes. An address in Mikage Town, Block 3. Late-night order records. There should be a log of ミナ's delivery in Fresh Line's system. "[sad]They were normal people. Someone who said thank you to me through the intercom." Silence filled the room. The warmth of the canned coffee transmitted through her palm. The "22:47" on the reasoning board quietly looked back at her. (Seven people placed their final order at this same time. Or were made to.) 藍子 looked at the board. She tapped the pen cap three times. "[serious]Let's go talk to Mifune-san." ＊ The Kagero Street arcade, bathed in early afternoon light, cast striped shadows through gaps in its deteriorating roof. Among the shuttered shops lining the shopping street, only the sliding door of Okame restaurant stood open. The smell of soy sauce and frying oil leaked from the entrance. ミナ opened the sliding door first. "[excited]Hello! One fried chicken bento, and some questioning, please!" Her voice was loud. The two customers inside turned around. Behind the counter, Mifune Toshiko looked up. Seventy-two years old. White hair pulled back tightly, wearing an apron. Deep wrinkles lined the corners of her eyes, and her smile was equally deep. She had the solid bearing of someone who'd witnessed all of Suirei City's changes. "[laughing]Questioning, like in a detective drama, huh? What is it?" Mifune began wrapping a bento while looking them over. 藍子 stood before the counter, lowering her gaze slightly. When an unfamiliar person's stare came straight at her, her neck stiffened a little. "[serious]Did you notice any changes in how the Fresh Line app worked about half a year ago?" Mifune's hands paused for a moment. "...Changes, huh." Mifune closed the bento lid, her expression becoming thoughtful. It was the kind of pause where she was pulling up memories. "[serious]Yeah, that's right. Before, the regulars would call directly or order through the app. I'd get 'the usual' from that person. But you know—" Mifune pushed the bento bag toward 藍子 and continued. "[serious]About half a year ago, orders started coming in under names I'd never heard before. Always around the same time, always similar requests. The money came through fine, so I didn't think it was strange, but—there was something off about it. The names weren't my regulars." ミナ repeated quietly, "Names that weren't regulars." 藍子 overlaid the testimony with the delivery records in her mind. Orders placed using the victims' accounts. Creating a record of late-night orders from Okame to fake their survival. Mifune's testimony corroborated it from the outside. "Those people," Mifune's voice dropped slightly. "They all died, didn't they?" ミナ nodded before 藍子 could. Small, but certain. Mifune's eyes grew slightly moist. She gripped the hem of her apron with both hands, then simply said, "I see..." The sound of frying oil was all that remained in the shop. The afternoon on Kagero Street grew a little quieter. ＊ They returned to Corpo Mikage just after three o'clock. 藍子 stood before the reasoning board still wearing her outdoor shoes and spread out the seven order time data again. She picked up her pen. She copied the seven numbers down in order from the top. 22:47. 22:47. 22:47. 22:47. 22:47. 22:47— When she wrote the seventh, her pen stopped. "[surprised]..." ミナ leaned in from behind. "[serious]This seventh one. The final order time for Room 704." "Yeah." "[serious]22:51." Silence. "[surprised]...Wait? The other six are all 22:47, but—" "Four minutes off. I confirmed it with second-level data. The other six are exactly 22:47 without a single second's variation. That's evidence of automated ordering—manual operation creates discrepancies." ミナ took the table. She checked. Six cases with matching numbers, one with a discrepancy. 藍子 wrote on the board. "Something happened in those four minutes." Next to it, another line. "The perpetrator was panicked." "[surprised]Panicked? Why?" "[serious]The victim was still alive. Someone saw them. The plan went wrong—in any case, they couldn't follow the normal procedure. The automated process had to be redone manually that night." ミナ set the table on the floor. She was thinking. 藍子 moved to the next data. Last week's night, the shift management log for 朽木 that she'd manually extracted from the timestamp accompanying the Fresh Line CSV. Data she shouldn't normally have access to as a courier, pulled from cache by timing the connection perfectly. She traced one line of the log with her finger. 22:47 to 22:54. There was a blank in 朽木's access log. Seven minutes. "[serious]Here." ミナ moved closer. She read the line 藍子's finger indicated. "[serious]朽木's access log has a blank for exactly these seven minutes. The order time discrepancy for Room 704 from 22:47 to 22:51—four minutes—is completely contained within the seven-minute blank." ミナ's words caught. 藍子 drew a double line on the board. "22:47-22:54 朽木 Access Blank" "22:47-22:51 Room 704 Order Discrepancy." The two lines overlapped. "[scared]藍子-san, that means 朽木-san—" ミナ started to speak, then stopped. "[serious]As circumstantial evidence, it matches." "[angry]But!" ミナ's voice rose. "[angry]I don't think 朽木-san is that kind of person at all. He was a good person, wasn't he? At the meeting, he was polite, he cared about the couriers—" "[serious]The log match is fact." "[angry]Facts alone don't tell you about a person!" ミナ said it straight on. It was the first time. She wasn't smiling. Her golden eyes looked directly at 藍子. 藍子 had no words. She was certain the logic was sound. The log match could be shown in numbers. As evidence it was weak, but the direction was clear. But she couldn't find the words to say "no." Why not. (I also—) Her thoughts stopped for a moment. She realized for the first time that there was an emotion within her that didn't want to conclude 朽木 was evil. The quality of his voice that night at the meeting. The warmth in it, the way it enveloped. If that had been an act—she couldn't make a definitive statement until she confirmed that possibility. That emotion had mixed into the edge of her reasoning. (This is a flaw in my reasoning.) Emotion had contaminated it. 藍子 froze before the board for several seconds. "[angry]Don't you actually think 朽木-san isn't suspicious either, 藍子-san?" 藍子 didn't answer. She was silent for three seconds. "[whispers]...I don't know." A short single phrase. She couldn't make a definitive statement. That word fell into the room as the first moment of her uncertainty. ミナ lost some of her momentum. Her angry expression softened slightly. A few seconds of silence. "[whispers]Sorry." "...Emotion may have entered my reasoning." "[gentle]I don't think that's a bad thing." "It lowers the precision of my deduction." "But reasoning without emotion isn't always right either, is it?" 藍子 didn't respond. ミナ didn't push. A different kind of silence came to the room. The kind that comes after anger passes, when you know each other a little more deeply. ＊ In the evening, 藍子 contacted 瀬尾 through the Fresh Line app's external chat. The four-minute discrepancy from 22:47 to 22:51. The match with 朽木's access log blank. She sent the numbers in bullet points. 瀬尾's reply came seven minutes later. "Access logs can't be used as evidence without a warrant. However, this discrepancy pattern could serve as grounds for a warrant application. I need one more piece of evidence." 藍子 looked at the screen and typed her next message. "I tried to check 朽木's GPS log. Area manager location data is on a separate server from courier logs.