Hwang Bo-un

When her pregnant mother leaves home with her boyfriend, Yujin finds a job at a pizza shop. Thanks to the people she meets there, she is able to find stability and love. However, the relationship with the lover as well as the relationship with her mother are challenging, and things get increasingly complicated. Yujin thinks she’s ruining everything.

A boy falls to his death at school, but Ok Chan-mi does not believe that her twin brother, Park Won-seok, committed suicide. Chan-mi transfers to her brother's school, Yongtan High, and meets Ji Soo-heon, who witnessed her brother's death. A "hero," who avenges bullied students, appears at Yongtan High. Chan-mi speculates that it may be connected to her brother and starts looking for this hero.