Kimi to Boku ga Kowashita Sekai

The second installment of the Sekai Series. The music room in the second semester at Kazusaen Middle School, where the clock tower is not repaired. The relationship between Byouinzaka Meiro and Kushinaka Choushi began there. The school's three eccentrics, Kushinaka Kogushi, Douno Kurori, and Gakemura Rouya, maintain a distorted balance. And then a murder occurs. The search for the culprit begins, with Meiro and Choushi playing detective, and the collapsed balance is further shattered... (Source: Kodansha, translated)

The fourth instalment of the Sekai Series. For him, everything is a game. Seven mysterious murders strike a prestigious girls' high school! A mysterious and inexplicable murder takes place at the supposedly peaceful Senju Girls' School. What's more, the person who works there is the ethics teacher, Kushinaka Choushi. Fourteen years have passed since the incident involving Byouinzaka Meiro. The search for the culprit in this game of detective starts again. Who is the culprit? (Source: Kodansha, translated)