Yuu has been living in a dormitory at a faraway school for three years since he left his parents' home. - Then, on the day of his graduation ceremony, which marks the end of his school life, his stepmother, Marina, runs up to him with a huge smile... - That night, at their graduation celebration, Marina was so happy that she drank too much and passed out. - Then, as a graduation present for him who dropped me off at my accommodation, I gently guided his hand to my chest... - Guided by her stepmother, whom she admires, Yu climbs the stairs to adulthood yet again.