In that summer, a boy confessed his love to the girl, and the two of them lived like a young couple in love every day... But because of the boy's grades, the two did not go to the same university. Gradually, their feelings gradually faded... After graduating from college, the two entered the palace of marriage, but for some reasons, the two did not end up in the end... On the day of divorce, the two had a car accident, and the boy left to protect the girl. But when the boy opened his eyes, he went back to the day they met in high school. The boy secretly swore that he would not repeat the same mistakes in his life.