Sayuki's a third-year student and runs the calligraphy club. She's pretty open about being a masochist—honestly, her whole thing is wanting to be Keiki's "pet." To make that happen, she's not above using hidden cameras to get blackmail material on him, which she then uses to pressure him into going along with her fantasies.
She clocked Yuika's crush on Keiki right away and decided they were rivals. The two are constantly at each other's throats, basically competing for his attention whenever they get the chance.
Content compiled by AnimeList.moe from publicly available sources.
