Yuu's student life of leaving home and living alone in a dormitory is coming to an end, and he is about to graduate.Then, on the way home from the graduation ceremony, the feelings he had hidden when he was reunited with his mother-in-law, Marina, who came running towards him with a smile, began to smolder again.That night, Marina drinks too much while celebrating her graduation just the two of them, and Yuu takes her back to the hotel...As he tries to suppress his urge to run out of control and leave the room, Marina gently kisses him and says, "Please accept my graduation gift..."And the boy was climbing the stairs to adulthood.
