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.

Eun Sang-Chul (Lee Sung-Jae) and his four children encounter difficulties after the sudden death of his wife. Then, a suspicious housekeeper named Park Bok-Nyeo (Choi Ji-Woo) appears. Because of the housekeeper, Eun Sang-Chul and his children faces various cases and family members who hate each other begin to experience love and reconciliation.

The drama is set in the backstage world of broadcasting industry. The story revolves around the dynamic work and life of people who work in entertainment division of television network.