Romance is sweet and bitter — and life riddled with ups and downs — in multiple stories about people who live and work on bustling Jeju Island.

Scarlet Heart: Ryeo is the remake of Chinese drama Bu Bu Jing Xin that stars IU as a woman who gets time-warped back to the Goryeo dynasty, and becomes involved with a very large family of princes, some of whom are vying for the throne, or her affections, or both.

Hyunjun and Sawoo, close friends and rivals from the South Korean special forces, are recruited by the secret agency NSS. They both fall for Seunghee, the beautiful but lethal profiling specialist at NSS. When they are faced against each other in a nuclear terrorist attack, they are forced to make their final decision and Seunghee's formidable secret is revealed.