Ritsuko Yasuhiro

Likes: Nosing in others' business, being the center of attention/being popular, relaxing, working as little as possible
Dislikes: Hard work, Shinn, mathematics, responsibilities

Ritsuko is the rich, snobby, and spoiled heiress of the Yasuhiro family. She met Shinn when she had just entered Haruka Academy, and the two never got along. Additionally, Ritsuko knows of Shinn's past exploits, and sees him as an asset to be used. She's also a heated rival of Satsuko and Touko, with whom she doesn't get along at all.