Jee - woon and screenwriter Park Hoon -
jung study the psyches of both the hero and the villain with equal interest, which makes I Saw the Devil one of the most character - driven tales of revenge ever made.
Sad faced, soft - featured young actor Lee Kang - sheng stars as a disconnected Taiwan youth
studying to get into college who becomes obsessed with a petty hood (Chen Chao -
jung) he witnesses vandalizing his father's cab.