Misaki Yonemura

Mei has been in love with Yuya all her life. They've grown up together. But when they reach their second year of middle school, Yuya suddenly professes his love for her older sister, Haruna.

Six classmates receive an email from Asuka, who they thought had committed suicide, asking them to meet her later that night. But when they are attacked by a girl in a rat mask, the students realize that someone is out for revenge!