A tenacious investigator goes undercover at a securities firm to expose corruption, but her mission is complicated by its new CEO — her former lover.

In Jeju, a spirited girl and a steadfast boy's island story blossoms into a lifelong tale of setbacks and triumphs — proving love endures across time.

Jeong Hoon is an anchor of a news show which has the highest ratings. Jeong Hoon’s handsome face and perfect body figure make him look good in a suit. Unlike his gentle appearances, he becomes a tyrant all of a sudden and starts asking aggressive questions to whoever it is. Because of hyperthymesia, he remembers every single thing happening in 365 days a year ever since his childhood. He can’t forget the memory of the woman he loved, Seo Yeon, who disappeared 8 years ago. A rising star who attracts everyone’s attention, Ha Jin, appears in front of Jeong Hoon at that moment. Despite all the attention, Ha Jin doesn’t waver and keeps her confidence. However, she has a secret that her memory is fading away. The man who cannot forget and the woman whose memory is fading away. Will they be able to overcome their difficulties, understand each other, and fall in love at the end?