Sayaka Sonohara

Sayaka Sonohara is Anri's mother and former Saika mother. Sayaka kills Anri's father and herself.

Saika Arc
Sayaka is revealed to be Anri's mother who tried to stop Mr. Shonohara from abusing Anri, but gets abused herself. One day Sayaka touches Saika and gets possessed by her. The night when Anri was nearly choked to death by her father, Sayaka slices off his head. After she cuts him, she commits suicide by slashing her neck, leaving Anri to be the new mother.