Aki Aoi is Sora's elder sister. Attractive, athletic, and intelligent, she's considered a model student at school. However, at home, she has no culinary talents and fails to keep her own room clean. She is deeply in love with Sora. She first attempts to have sex with Sora in the shower but is unsuccessful. However, her second attempt, in his room, is successful, and they have engaged in sexual intercourse several times since.