Min-hee, who faces many changes after losing her husband. After her husband's sudden death, Min-hee visits Jeju Island, where her husband had always yearned and experiences a whirlwind of emotions. Mok-ha, a single mom living in Jeju Island, becomes a neighbor to Min-hee who comes down from Seoul and causes various emotional changes.

The president has disappeared one day. His body hasn’t been found but he’s not returning. Cheongil Electronics is now buried in debt, and all the employees are desperate to survive. Sun Shim is a bookkeeper whom everyone belittles. She’s sick of her life and dreams to be a shareholder of Cheongil. With Mr. Oh’s disappearance, Sun Shim, who knows nothing, becomes the next president.

Baek Chan-Mi was a legendary black agent for the NIS, but, due to her excessive work, her subordinate died and she missed catching her intended target. Baek Chan-Mi was punished for that botched case and she now works in a cyber security team for the NIS. Baek Chan-Mi is then selected to go undercover on a case involving intellectual property theft at Korea's largest company.