Iyo Yamaguchi

Iyo Yamaguchi is the younger sister of Kenji Yamaguchi. She is a minor character, appearing as a first year student in Syoyo High School. Iyo appears as the story's extended antagonist, but in a chapter of volume 13, she is the main heroine or good character. Iyo always refers herself in the third person. She enjoys flirting, as she tries to attract both Haru and Yuuzan right after meeting them. Iyo longs for a boyfriend, but remains single throughout the series, possibly because of her self-centeredness.