Years after a K-pop star saves her life, a fan learns of his death — but when she's suddenly transported to the past, she sets out to change their fate.

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...

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