Ji-woo, an outcast at a prestigious private school, meets Hak-sung, the school janitor who is actually a mathematical genius who defected from North Korea.
최민식
as Ri Hak-sung
김동휘
as Han Ji-woo
박해준
as Ahn Gi-chul
박병은
as Kim Geun-ho
조윤서
as Park Bo-ram
탕준상
as Tae-yeon
김원해
as Park Pil-joo
주진모
as Professor Oh
김희정
as Bo-ram's Mother
강말금
as Ji-woo's Mother
주예린
as Korean Teacher
정승길
as NIS Agent
