

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.
Ok Chan-mi

Ji Soo-heon

Seok Jae-beom

Ki Oh-seong

Gook Ji-hyun

Tae So-yeon

Jin So-jeong

Hong Ah-jung

Sa Joong-kyung

Lim Seung-woo

Ma Nak Joon

Park Won Seok / Ok Chan Kyu
