The little ruffian Li Yideng suddenly traveled to the 1970s when big-character posters were plastered all over the place. He was picked up and taken home by Professor Chen. In the Chen family, the orphan Li Yideng felt the warmth of the family. He decided to use the historical knowledge he learned in modern times to save the family and save his family from the pain of rape. But it seems that his fate cannot be changed. During the days when he was sent down to be an educated youth, Li Yideng gradually discovered that he fell in love with Professor Chen's daughter, his little sister Chen Zhengran.