Korekiyo is a slim, tall young man. He is 17, has a sick sister at home. His parents are not very attentive. According to Korekiyo, he had an older sister who meant the world to him and knew him better than anyone else. She always had terrible health, and ever since Korekiyo was young, she constantly had to go in and out of the hospital. She was horribly lonely and never had any friends, so she spent a lot of time with her brother. He is a shy, introverted boy. Yet very intelligent youngster.