One day, the male protagonist Xu Yi, who was fooled by the principal, met a boy who called himself "Wu Yun" on his way back to the class room to clean up. The big thief - the boy was holding his family heirloom. After some twists and turns, Xu Yi was shocked to realize that the boy was a "seraph"! And later, Xu Yi discovered that the angel was his father? What happened?