Keiko Numata

Keiko Numata is Ikuo Takabayashi's grandmother and Kensaku Numata's wife. She is the proprietor of Sakitani Kinenkan along with her husband.

Appearance
She is an old lady with brown short hair and brown eyes. She wears a white t-shirt and a yellow apron.

Personality
Keiko seemed a kind, gentle and warm-hearted grandmother. But she proved to be an insane crone and a murderer.

Plot
Keiko was first seen in episode 10, when she and Kensaku welcome part of Class 3-3 who came at the Yomiyama Shrine to pray for their safeness, hoping that this action would stop the calamity. The class was accommodated at her restaurant-pension. In Episode 11, she was revealed to be the killer. After Yuuya Mochizuki and Naoya Teshigawara found her in a room with a bloody knife, she attempted to kill them. In the process, Yuuya pushed her away from Naoya, causing her to drop her knife and wound the latter's leg. She continues after the two down the hallway. Keiko also killed her husband in a very brutal way and started a fire in the dinning room prior to this. After Mochizuki and Naoya escapes from Keiko, he opens an emergency door and Keiko was inside waiting to kill them The reasons for her insane actions are still unknown. In Episode 12, when Mochizuki and Teshigawara escape by the window, she grabbed on Mochizuki's leg and both of them rolled out of the window. She grabbed on Teshigawara and wanted to kill him but instead, killed by Chibiki-Sensei. Near the end of the episode, Chibiki mentioned that they were Takabayashi's maternal grandparents, and they were emotionally depressed about his death.

Trivia

 * In the original novel she killed Manabu Maejima,  Izumi Akazawa, Takako Sugiura, Junta Nakao, Shigeki Yonemura and her husband with a knife at Sakitani Kinenkan and then proceeded to commit suicide by bitting off her tongue. The reason for this wasn't revealed in the original novel and still remains unknown.
 * Her first name, Keiko mean "blessed child". It's ironic that her name mean "blessed child" when she killed 5 students, her husband and then committed suicide.