Who's That Knocking at My Door? (2007)

Who's That Knocking at My Door? 2007 / 저수지에서 건진 치타 2007 / Jusujieseon geonjim chita

A young loner named Je Hwi was tormented and bullied by a classmate named Pyo in high school. Now a young adult, Je Hwi begins to open up to his girlfriend Jang Hee. However, a revenge plot he had hatched against Pyo with a stranger he met over the internet, begins to grow way out of control with cruel and unpredictable results. (Source: AsianCrush.com)