
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.

as Ok Chan-mi

as Ji Soo-heon

as Seok Jae-beom

as Ki Oh-seong

as Gook Ji-hyun

as Tae So-yeon

as Jin So-jeong

as Hong Ah-jung

as Sa Joong-kyung

as Lim Seung-woo

as Ma Nak Joon

as Park Won Seok / Ok Chan Kyu

as Hwang Soo-na

as Gu Ja Taek [Yongtan High School's Teacher]

as Park Na-rim