Aki Sora

Sora had become nervous around his older sister Aki, since he had started having lewd thoughts about her. While taking a bath together, Aki masturbates Sora, who runs off in disbelief. The next day, Sora cannot face Aki and runs off, inevitably getting locked in a store room. Aki eventually finds him and the two kiss, later returning home to make love.

Sora continues his incestuous relationship with his sister Aki, keeping it a secret from everyone else. Meanwhile, his twin sister Nami forces him to join the Fashion Research club which her friend Kana Sumiya, who has a crush on Sora, is a part of. While Sora looks after Aki, who catches a cold during one of their secret get-togethers, Nami, who is secretly in love with Kana, asks Kana to pretend she is Sora while they practice kissing.