yuu, who is about to graduate, has finished her life at a boarding school after leaving her parents' home. she left home to shake off her feelings of love for her stepmother, Yuki, but the moment she reunited with her waving and running towards her on the way home from the graduation ceremony, her hidden feelings quietly reignited. that night, yuu sends the drunken yuki, who has let loose at a graduation celebration for the two of them, to her lodging. yuu tries to suppress her raging desire, but she gently kisses him, saying "as a present for you who has become an adult..."
