Lunch break at the school. There is a place where the siblings Ryosuke and Yayoi can be alone and undisturbed. Why do they meet in secret? That is because they are more than brother and sister. Sex is on their lunch menu. However, only anal, because they are siblings, and Ryosuke is vary to cross the last line. Yayoi is full of happiness because she loves her elder brother, a love she feels will last for all time...

How long has it been...? Since her homeroom teacher deprived her of her virginity, Yayoi has been called up almost every day and in various places at the school, so Yayoi have been a mess. However, Yayoi's reasoning has not been lost. Her unwavering feelings for her brother Ryousuke have supported her. Ryousuke is worried about Yayoi, and at lunchtime presents a gift for her. Yayoi immediately attaches the the pink ribbon given to her. Ryousuke smiles at Yayoi who looks happy. However, the tranquillity is torn away by the ringtone of a telephone.