Yuu left his parents' home and went to a boarding school. He successfully completed his studies and finally graduated. As he was heading home, sad to say goodbye to his classmates, he saw a woman waving and running towards him from across the street... It was his stepmother, Rinka, who wasn't supposed to be there. Yuu couldn't hide his joy at being reunited with the person he once loved. That night, the two of them drank too much at the graduation celebration and Yuu sent Rinka off, asking, "Will you accept this graduation gift from your stepmother?" She gave him a gentle kiss...