Ningyo

Age: Considered to be around 100 
Hobbies: Pretending to be human 
Likes: Unknown 

The mysterious doll that took countless human lives and led Tamura to his five-year-long ordeal.

Her true identity is a doll born from a wish for her to be human. The whole incident was the result of the actions the doll took to pretend to be human, and there was no malice involved.

Her looks strikingly resemble the doll maker's little sister, who died young.