Daisuke Goura is clearing his late grandmother's belongings and comes across an autographed copy of And Then by Sosuke Natsume. When he visits Biblia Antique Books for an appraisal, he meets the store's beautiful young owner Shioriko. Just by taking the book into her hands, Shioriko instantaneously reveals that it hides a secret that Daisuke's grandmother took to her grave: She once had a love affair with the owner of the book, and that man could probably be his grandfather. Impressed by Shioriko's analytical skills, he cuts a deal with her to help out at the store since she cannot do any heavy lifting due to a recent leg injury. As they are drawn to each other and become more intimate, Shioriko shares a surprising secret with Daisuke: Someone who is after her rare copy of The Final Years by Osamu Dazai, has been continually threatening her – and to make matters worse, he was the cause of her injury. Who is this mysterious man? And what happened to Daisuke's grandmother 50 years ago? The secrets of the antique books are to be revealed.