On Wednesday of the fourth week of summer vacation, in the Library administrator's duty office, Shiina Hiyori sat before three monitors. The screen on the left displayed an index of Old System provisions; the one in the middle showed the final confirmation page for the Uninhabited Island data archive; the one on the right listed archives scheduled to be opened during summer vacation. The cold glow of the three screens cast tiny points of light in her pale chestnut eyes. Her fingers tapped steadily across the keyboard as she uploaded the final batch of appendices for the cross-class group reports to the school's central database. When the progress bar reached one hundred percent, she let out a soft breath and picked up the tea beside her for a sip. It had gone cold, but the rim of the cup still carried a faint scent of bergamot.
She worked three shifts a week during summer vacation. Not because the Student Council required it, but because she was the only administrator capable of precisely locating every Old System provision within this outdated indexing system. When Sakagami retired the previous week, he transferred the last batch of manuscripts from his private bookshelves to the Library and specifically assigned her to archive them. These manuscripts contained the original minutes, revision records, and reasons for repeal for every provision frozen since the school was founded. One folder, numbered ARC-0041, caught her particular attention. Written on its cover in slender-gold script were the words—"Original Draft of the Asymmetric Observer System and Revision Comments from Each Iteration." While organizing the drafts, she unexpectedly found a yellowed borrowing slip. The borrower's signature field contained only one symbol: "&." The borrowing date was two weeks before the cross-class group task began last semester—an entire half-semester before Sakagami first mentioned