If You Are Happy

After her fiancé unexpectedly calls off their wedding, Lin Beixing is transported back to her high school years through a mysterious glitch on her old phone. There, she reconnects with Zhang Wansen, a brilliant classmate doomed to a tragic fate. Realizing she can alter the past by deleting old messages, Lin sets out to change both their destinies—and discovers a second chance at love and self-discovery.

Zhang Wansen plans to confess his love to Lin Beixing, a girl he has had a crush on for a long time after the college entrance examination, but the sudden concert accident turned everything into an irreversible tragedy. Helpless Zhang Wansen unexpectedly restarted this summer, and returned to Lin Beixing before the tragedy. The secret of restarting summer seems to be not as simple as imagined...