Mamimi Samejima

Mamimi Samejima is a truant high school student with a quixotical grip on reality who carries a camera and smokes most of the time, hinted to have been bullied at her school and apparently from a broken family as her parents are mentioned are separated or are out of her life. She was originally Tasuku's girlfriend since he saved her from a elementary school fire, which she apparently caused due to her pyromaniacal tendencies to burn things she hates like her old school. It became a ritualistic practice for her in worshipping her personal deity Cantido whom she considered Canti an incarnation of.

While Mamimi conceals her destructive nature, her aura of benign morbidness does make her an outcast in the eyes of others, save Naota who had a crush on her. Most characters refer to Mamimi simply as Mamimi, but Naota's friends refer to her as "Naota's wife", and Haruko calls her "Sameji", a shortening of her last name. Amarao refers to her as "that high school girl".

Her relationship with Tasuku was ultimately based on caring for those who are dependent on her, having a habit of naming things "Ta-Kun" like a black kitten, and leaving them the moment that show any independence. Mamimi entered a sort of relationship with Naota as a means of coping with Tasuku having left for America and getting a new girlfriend, calling him "Ta-Kun" before he realized she was using him and emotionally explodes about her using him as a consolation prize during the events of Brittle Bullet while vowing to win her love.