Contains one story and 2 side stories. Main story: Yue lives alone with her 27 year-old step father, Kouki. She's dating a boy her age...but she can't stop thinking about Kouki. Could it be love? Side story 1: Koukando Equals. Side story 2: Diamond.

義理の父・光基のことが大好きでたまらない有笑。だけど、今の生活を壊したくなくて、想いは胸に秘めたまま…。“親子”としてしかそばにいられない、そんな切ない有笑の恋の行方は…。　【同時収録】ダイヤモンド