Once rivals in school, two brilliant doctors reunite by chance — each facing life’s worst slump and unexpectedly finding solace in each other.

Seul Gi gets a new job at a chocolate company and works hard, but can't seem to adjust to its atmosphere. She tries to overcome her alienation with her positivity, but constantly gets hurt. One day at Honggeumdang, a place she visited to fix her broken watch, she falls in love with the charm of handmade chocolate. She soon becomes the only member of a task force for an in-house contest for Valentine's Day and collaborates with the owner of Honggeumdang to create the best chocolate ever. However, it isn't easy to find teammates. Just then, Hyun Nam, the chocolate maniac, and Jeremy, the extrovert social media influencer, appear. Will the unique trio and the strangely cool Mr. Hong be able to create the ultimate chocolate that will charm everyone on Valentine's Day?

Cha Wooseok (Wi Hajun) receives a mysterious call from an informant who claims to have evidence of a fraud-related murder. Before revealing the truth, the informant falls to her death. Wooseok’s investigation leads him to Royal Auction and its chief auctioneer, Han Seol-ah (Park Minyoung), whose three fiancés have all died under suspicious circumstances. To expose the truth, or perhaps to test her, Wooseok proposes they fake a relationship. As he uncovers her secrets, he realizes he may have stepped into a web he can’t escape—and that getting out could cost him everything.