Yu attends a boarding school. The fun student life ended in a blink of an eye, and on the way home from the graduation ceremony, a woman ran up to Yu with a smile in the eyes of Yu walking with his friends. The person who visited with a smile was her mother-in-law, Hijiri, who was secretly in love. Yu is excited about the celebration of the two of them with her lover. - That night, when I drank too much and sent my girlfriend to the inn ... Hijiri, who accepts his feelings, kisses him gently, saying, "It's a gift from me." And Yu begins to take a step toward adulthood.