고등학교 도서실을 배경으로 수수께끼를 풀어나가는 일상 미스터리. 호리카와와 마쓰쿠라가 2학년이 되어 학교 도서실 도서위원이 되면서 함께 수수께끼를 푸는 과정을 담고 있다. 할아버지가 남긴 금고의 번호를 찾아달라는 도서위원 선배의 의뢰를 담은 「913」, 함께 머리를 자르러 간 미용실에서 우연히 맞닥뜨린 사건을 푼 「록 온 로커」등 모두 여섯 편의 연작 단편이 실려 있다.
각각의 수수께끼를 풀어나가며 호리카와와 마쓰쿠라의 우정 또한 발전해나간다. 2학년이 되면서 도서위원으로 처음 만나 알아가기 시작한 두 사람은 특별히 ‘우정’이라고 부를 것 없는 관계였지만, 하나둘 에피소드를 거치며 겉으로 드러나는 모습이 아닌 상대가 생각하고 느끼는 점들을 알아차리기 시작한다.
Honobu Yonezawa (米澤穂信), Yonezawa Honobu, born 1978) loved making up stories even as a child and began writing fiction at the age of 14. By the time he got to university he was posting stories on his own website. After graduation he continued writing while working in a bookstore, and first got into print in 2001 when Hyoka (Ice Cream), a YA mystery novel he submitted for the Kadokawa School Novel Prize competition, earned an honorable mention. Sayonara yosei (Farewell, Sprite), a critically acclaimed story of the relationship between Japanese high-school boys and a girl from war-torn Yugoslavia, helped cement his reputation when it was published in 2004. Since then he has been a regular presence on lists of the year's best mysteries. Oreta ryukotsu (Broken Keel) won the Mystery Writers of Japan Award for Novels in 2011. Though known especially for his distinctive and fresh blending of the tale of youth with the whodunit, Yonezawa has also made forays into science fiction, as with 2006’s Botorunekku (Bottleneck) and 2007’s Inshitemiru (Try Indulging), a sinister "murder game" story. In 2013 he published the novel Rikashiburu (Recursible). He is a leading figure among Japan's younger generation of mystery writers.
The characters are developed slowly over the course of the short stories. I really ended up liking all of these and I really appreciated how the author didn’t go for a nice happy ending in all the cases but instead leaves the reader with some frustration over the ending.