Two professors secretly met at the back of the school with a cup of coffee. The battle of cutting water with a knife begins.

In his 40s, the stuntman Woo-seok wishes to go back to the prime of his life in 1997, before a facial scar ended his acting dreams. One day, he purchases five talismans from an unknown monk, hoping to change his life. However, during a film shoot, a car accident transports him back to his high school days in 1997. Now living as the high school student, he embarks on a project to revamp his past life, which was filled with a troublesome father, son, and husband.

Seong-joon, the heir of Tae-baek martial arts, leaves his life of seclusion in search of Jin-su, a senior member of his discipline. On the way, he meets Bo-mi, the love of his life and realizes martial arts is useless to live, renouncing the ways of the martial arts. Instead, he opens an acupuncture clinic using the knowledge accumulated from his training.

A young woman gets into male-only prep school.