Cinderella wa 6-gatsu ni Kieta

Yuri Takizawa, the most popular girl at school, has mysteriously disappeared... To find clues to her disappearance, the homeroom teacher Tsukishima gathers her best friend Tomoe Aida, her childhood friend Toru Himuro, and Hiroto Watanabe, who confessed to Yuri on the day of the incident, in his classroom to find out what happened. But...! This is a romantic mystery that reveals the truth of the case from various perspectives! (Source: Shogakukan, translated)