Kanako Hosokawa is a first-year student at Lillian Girls' Academy, sharing a class with Noriko and Touko Matsudaira. Standing 179 cm tall with black hair and brown eyes, she maintains a quiet, unapproachable presence, often appearing as a solitary "lone wolf" during breaks with no apparent social ties. Her deep aversion to men originates from her father's affair with her former senpai, Yūko, resulting in a child. This event cemented her view of men as "the lowest possible form of life" and fueled a desire to protect idealized purity. The subsequent separation of her parents caused significant turmoil; she solely blamed her father, unaware of key details about his relationship with Yūko. Kanako develops an intense fixation on Yumi Fukuzawa, idolizing her as perfection incarnate. This escalates into stalking: she frequently appears in the background of Yumi's photographs and follows her outside school, meticulously noting interactions with males like her brother Yuuki or Suguru Kashiwagi. She volunteers at the Yamayuri Council's Rose Mansion primarily to be near Yumi, sparking speculation about becoming her petite sœur—a possibility Kanako publicly dismisses as "lowly ambition". Her obsession strains the relationship. When Yumi plans to attend the Hanadera Boys' Academy festival, Kanako urges her to avoid it, citing the "danger" of men and Yumi's perceived naivety. After Yumi refuses, Kanako reacts with hostility, accusing her of betraying her pure image. This draws criticism from Sachiko Ogasawara, who challenges Kanako's right to impose expectations. A pivotal moment occurs during Lillian's school festival when Kanako encounters Yūko and her father. She learns they have been in a committed relationship longer than she knew and meets her infant half-sister, Chikako. Yūko embraces Kanako, who tentatively holds Chikako, leading to reconciliation. This experience helps her accept reality over clinging to an idealized past. Following this, Kanako shows development. She continues assisting the Yamayuri Council and joins the basketball team. She maintains her stance against becoming Yumi’s petite sœur, clarifying it was never her true intention. Her relationship with Touko Matsudaira remains tense but less adversarial, though they are unlikely to become close friends.