A middle-aged man time travels to the past to become a teacher to his 17-year-old classmates. Hao Hui Gui is a 36-year-old high school teacher who is still single. During a gathering, he gets into a huge disagreement with everyone present and even gets into a fistfight with his best friend. Upon returning home, he mindlessly flips through his personal diary from 20 years ago and starts to recall many memories from the past. He falls asleep eventually and meets with his younger self in his dreams.

Set off by a sweet chance encounter, 16-year-old Su Zaizai finds herself helplessly drawn to Zhang Lurang — her smart, charming yet distant schoolmate.

Chu Qi, the young lady of Shen Mansion, searches for her missing sister, Shen Shisan, and clashes with the medicine vendor Wang Wu, who later mysteriously dies. Accused by investigating officer Wu Xu, Chu Qi breaks into a charity house for clues and assumes the identity of "Officer Wu" to infiltrate Fengming Town. There, she discovers villagers dying under strange circumstances while Wu Xu and childhood friend Gu Yusheng arrive to uncover the truth. As they delve deeper, the tragic fate of Shen Shisan is revealed, and the dynamics between the trio shift, unaware of a hidden puppeteer orchestrating events.

Small town girl Fang Li and the stone-faced straight-A student Luo Yan relive their forgotten days from high school after reuniting in college, thus starting their journey of love that's filled with endless bickering. Fang Li and Luo Yan became classmates during their freshmen year of high school. For Fang Li, Luo Yan's existence was a nightmare. Three years later, they meet again as university students. Luo Yan no longer remembers Fang Li from that time, but the battle between the sunny girl and the proud devil has just begun. The two "enemies' experience the best times of youth together, recovering the beauty that was once lost and finding the path to their own dreams.