The TV anime adaptation of Biblia Koshodō no Jiken Techō will begin airing in April 2027, according to an ORICON NEWS report published on October 3, 2026. The same announcement brought the first promotional video, four additional cast members, and character visuals for the leads, Shioriko Shinokawa and Daisuke Gōra.
Riko Akechi voices Shioriko and Shunsuke Takeuchi voices Daisuke. The four additions are Reo Osanai as Ayaka Shinokawa, Wataru Takagi as Shida, Yōhei Azakami as Kikuya Kasai, and Saeko Kamijō as Nao Kosuga. All four characters appear in the video alongside the leads, and their voices can be heard in it.
The series is a mystery about Shioriko, who runs the secondhand bookshop Biblia Koshodō in a corner of Kamakura, and Daisuke, a young man who works there, as the two untangle puzzles and secrets surrounding old books. It is based on En Mikami's literary mystery novels, published by KADOKAWA under its Media Works Bunko imprint with illustrations by Hagu Koshijima. Cumulative circulation for the novel series has passed 8.5 million copies.
In comments carried with the announcement, Osanai described Ayaka as a bright, sociable girl whose personality is the opposite of her older sister Shioriko's, and said the warmth particular to the two sisters is one of the work's appeals. Takagi said Shida looks like a suspicious middle-aged man at first glance, but that nobody beats his passion for books or his skill as a used-book reseller, and that he enjoyed trading lines with Akechi and Takeuchi. Azakami noted that his character, Kikuya Kasai, is a reseller whom Shida calls "Baron."
Mamoru Kanbe is directing, with Toshiya Ōno on series composition, Jun Nakai as character designer and chief animation director, and Takahiro Obata composing the music. CloverWorks is handling animation production.