Seo Ha Eun was adopted when he was seven years old and doesn't remember anything from before that time. The only thing from his past is a police badge from his father, so he became a police man. He is in love with Eun Ha, his adopted sister. But then he comes to know that not only does he have a twin brother, but his real father was murdered. After another tragedy happens, he leaves his adopted family and his love Eun Ha to seek revenge.