Chika Midarezaki

Formerly known as Senko Himemiya (姫宮 千子, Himemiya Senko), she is Yūka's biological sister and is the last one to join the Midarezaki family. She was the former 'Solitary Doll' before Yūka was born. After Yūka became the next 'Solitary Doll', she tortured her in various ways and even gave money to her classmates to bully her. However, she remembered the promise with Ginichi Kizakura, now Ginka Midarezaki, and regrets her wrongdoings. She actually doesn't have Enka's DNA, but she becomes a member of 'Peaceful Family Operation' by Kyōka's ability.