Kaoru is an individual with both male and female characteristics. She is one year older than Nanako but attends the same class due to a mysterious illness that prevented her from attending school for a year. Despite being known as the "class-leader" and captain of the basketball team, Kaoru has a compassionate heart and cannot tolerate injustice or abuse of power. Her nickname, "Kaoru-no-kimi," is derived from Kaoru Udaisho, a character in Genji Monogatari who was renowned for his beauty and the divine scent emanating from him. Kaoru is celebrated for her vibrant energy and profound love of life. She is believed to be Saint Just's closest companion, deeply caring for her while often becoming enraged at Reis disregard for her health. Although she ended a deep relationship with someone close to Nanako, Kaorus heart still holds a special place for this person.