Chen Xin, a 28-year-old social worker, learned at his ten-year high school reunion that the transfer student Lin Xi, whom he had a crush on, would marry someone else. He fell asleep drunkenly with endless regret and loss, and when he woke up, he found that he was back in the senior high school classroom when he was 18 years old. Everything was reshuffled, and he had a golden opportunity to make up for two major regrets in his life: getting admitted to the university of his dreams, and bravely confessing his love to that girl.
