Momoka Oginome
Ringo’s older sister who died in a subway explosion on the day of Ringo’s birth, and the original owner of her diary. She was friends with both Tabuki and Yuri.
Her diary is allegedly one that can transfer the fate of individuals, such as preventing someone from dying. However, these transfers inflict injuries on the user as payment, with more drastic fate transfers resulting in larger and even fatal injury.
It is revealed in Episode 23 that she was divided into the two penguin hats by Sanetoshi.