Shang Ming (Jin Laiyuan), a 24-year-old college student, received an incredible order from his grandfather: he must marry Bao en (Wen Genying), a 16-year-old middle school student. It is said that this is the promise of the previous generation, but let these two people from different worlds, eight years apart, inexplicably set foot on the marriage hall. This marriage, which came too early, made Bowen very unaccustomed. She was in love with the boy on the baseball team, got married and secretly went out to date him. Shang Ming is still a responsible man, no matter what, he wants to take good care of his little wife, until he works as a trainee teacher at Bowen School, embarrassment comes one after another! He could not let others know that he had a 16-year-old wife, but also had to resist the pursuit of a young female teacher, and his marriage to Bowen was even more uncertain.