The film follows the story of celebrity Oh Sun-hee, played by Jung Hye-in, who returns to her hometown of Wando after filing for divorce from her opportunistic husband who appears to exploit her fame for his business ventures.

On the island, she gets to reunite with her childhood friends, including her first love, Jo Dong-pil (Choi Daniel), who ended their relationship after enrolling at Seoul National University to pursue his studies.

Once an ambitious and promising law student, Dong-pil now lives in a makeshift tent near his parents' gravesite, seemingly having abandoned his legal career to inherit his father's old fishing vessel.

Upon learning that Sun-hee's husband had been secretly plotting to transform the serene island of Wando into a resort village without sharing the plan with her, Dong-pil and the townspeople join forces to stop him from pushing forward with his relentless development scheme. Through these events, Dong-pil discovers a renewed sense of purpose in life, and his long-dormant feelings for Sun-hee rekindle.

For over a decade, the two protagonists have walked separate paths, dedicating themselves to their careers and navigating life's ups and downs, with Sun-hee struggling with the pressure of fame and a wrong marriage and Dong-pil losing his parents in a tragic accident at sea.

Eventually, they find their way back to each other, realizing that in the end, what truly matters isn't fame or fortune, but having someone who understands and is willing to stand by them through life's darkest moments.

A still cut from "Sunny Day" is seen in this image provided by Samgeori Pictures. (PHOTO NOT FOR SALE) (Yonhap)

A supporting couple -- Cha Young-sook (Kim Jung-hwa), once Sun-hee's high school rival and Ha Seok-jin (Han Sang-jin) who is Dong-pil's best friend and once had a crush on Sun-hee -- brings light-hearted, wholesome humor to the narrative.

In the film, Wando and nearby Cheongsan Island almost act as important characters in their own right, with their tranquil charm underscoring the story's themes of healing and comfort.

Growing up in the southwestern city of Gwangju, director and scriptwriter Lee Chang-moo chose these islands as the film's location, having visited them frequently in his childhood and been captivated by their scenery and serene beauty.

Without relying on dramatic twists or tension, the film gently leads viewers to contemplate a simple truth: life is made up of small moments, not grand schemes and behind great fame can lie an empty heart. For those craving adrenalin-pumping, thrill-packed scenes, it may feel somewhat slow-paced.

"Sunny Day," which was officially screened at the 28th Bucheon International Fantastic Film Festival last year, is set for release on Feb. 19.

A poster for "Sunny Day" is seen in this image provided by Samgeori Pictures. (PHOTO NOT FOR SALE) (Yonhap)