On Seon-woo is the head of the biggest company in Korea. He also secretly runs a private detective agency. On the other hand, Don Se Ra is a person with extraordinary vision and uses this ability to help people...

Cha Do Hyun is a rich heir to a family company with one major problem. Due to suppressed childhood trauma, he suffers from dissociative identity disorder manifested in 7 unique personalities who are out of his control. In order to overcome this disorder in secret, he hires a first year medical resident to help him heal by killing off each personality one by one.

Two very different restless youths join a swimming competition for love and friendship which is, in fact, a rite of passage to growing up.