A quiet but hot headed, weak-willed, girl who has experienced trauma at the hands of those who hurt others. Over time her internal pain has transformed into an obsessive drive to end that sort of behavior, even killing to do so. She's friends with Mahiru Koizumi, and hates Natsumi Kuzuryu for threatening her friends, Sato also despises yakuza. Sato's had her eyes on Natsumi for a long time and is getting close to her snapping point. Especially after seeing her bully Mahiru Koizumi.