Airi Shishibuki

Ruka's stepsister. In the winter of her first year of middle school she suddenly fell into a coma. Well-mannered and caring. Because she doesn't bother others, she was able to het along with Ruka, who doesn't easily get used to other people. She is aware that Amazakura and her heart are linked, and has a secret that she has not told Ruka. She had a twin sister who was killed in a car accident in her third year of grade school.