Kei's mother with B-ko's father Teru.

Kei Yūki (結城 桂) is a rad biker dude who nearly runs over C-ko when she runs into the street. A-ko knows him down. He later runs into her at her part-time job at a fast food joint, and gives her a ride to meet C-ko, who dislikes him. He carries the earring that C-ko dropped. His favorite movie is Tabidachi - Ami Shusho. He is later engaged to Ayumi.