Кёка Мицуба

She is the younger sister of Mamoru, also in the same grade as Himeno. She has feelings for Keigo. She was happy that Himeno loved her brother and supports them but eventually becomes angry with her since Himeno develops feelings for Keigo. She also gets jealous of Himeno due to Keigo's relationship with her and gets the whole school to go against Himeno. In the end, Kyouka accepts the fact Keigo loves Himeno.