Samejima Mamimi

Mamimi Samejima (サメジマ・マミ美, Samejima Mamimi) is a high school truant and Tasuku's ex-girlfriend. She is a lonely and depressed chain-smoker, and a pyromaniac. She adopts several pets and names them all "Ta-kun" (タッくん Takkun) as a replacement for Naota's brother, including Naota himself, but later grows uninterested when Naota exhibits independence. Her name is written in Katakana in the manga panel scene, which suggests she is not entirely Japanese.