Aoi Kirishima  

, 桐島 葵

Harutos elder sister returned home from college in Tokyo to teach as a student teacher in order to obtain her teaching license. Although she is the least mature among the two siblings, she lives next door to Yamato Akitsuki in Ayano Fujikawas dormitory in Tokyo. She showed Haruto a picture of their first meeting when they were children. In comparison to him and Nanami, she believes that Haruto and Yuzuki make a better couple. Despite being a heavy smoker, extremely lazy, and leaving her room messy, which often results in Haruto having to do most of her chores. Prior to getting his own apartment, Haruto lived with Aoi in the dormitory.