Yuu's student life living alone in a dormitory is coming to an end, and he will soon be embarking on a new journey. On the day of her graduation ceremony, the person who ran across the street with a smile on her face was her stepmother Haruka, who she was secretly in love with. They spend their graduation celebration together, but she is so happy with his growth that Haruka, who is defenseless of her, ends up getting drunk. Yu desperately tries to rid her of her evil heart and sends her to her hotel. However, Haruka was aware of his feelings and kissed him gently, saying, ``This is a present for you, Yuu, who has grown up.''
