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.
Cast: Choi Min-sik, Kim Dong-hwi, Park Hae-joon, Park Byung-eun, Jo Yoon-seo, Tang Joon-sang, Kim Won-hae, Ju Jin-mo, Kim Hee-jung, Kang Mal-geum
