The story of a "mystery" interwoven with old books and people begins.

North Kamakura. Biblia Koshodou is an antiquarian bookstore that quietly stands in an alley near the station. The store not only buys and sells antiquarian books, but also provides "special consultations" related to antiquarian books.
In early spring, when it is raining lightly, a new consultation comes in: a mystery surrounding a collection of about 1,000 books left behind in a certain antiquarian bookstore. The owner of Biblia's antiquarian bookstore, Shioriko's daughter, a high school student named "Doako Shinokawa," faces a situation in which various people have their own agendas.