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

“Dear.M” will tell the story of the campus-wide search for the mysterious “M,” an individual who is mentioned in an anonymous post on a Seoyeon University online community. The realistic romance drama will follow the changing relationships and budding romances between various characters in the wake of all the buzz about “M.” Ma Joo-A is a 2nd year student in the Business Administration Department at Seoyeon University. She has a warm heart and bright personality. She is not interested in pursuing a dream or having a romantic relationship. She has never had a boyfriend before. Cha Min-Ho is a 2nd year student in the Computer Science Department at Seoyeon University. He has a talent for developing apps with innovative ideas. He has been friends with Ma Joo-A for 12 years. Seo Ji-Min is a student in the Economics Department at Seoyeon University. She is also a member of the schools cheering squad.

About the unexpected romance that occurs as Jin Moo Hak tries to steal an art museum from Kim Dal Ri. Kim Dal Ri, who was a visiting researcher at Kröller-Müller Museum and then becomes the director of Chungsong Art Museum. She is a character whose speech and actions are always classy and considerate. Dal Ri enjoys studying diverse fields such as art, philosophy, and religion, and she is proficient in seven languages. Jin Moo Hak, whose family grew a tiny gamja-tang (spicy pork back bone stew) restaurant into the global food corporation DonDon F&B. Although he is a director of the company, he is far from intelligent and was always ranked last in his class when he was in school.

The story of Park Jin Sung who owns a late-night snack restaurant.

A turbulent twister of lies, betrayals and revenge tears apart the seemingly picture-perfect marriage between a doctor and a filmmaker.

Jung Young Jae is a promising young surgeon, but her cheerful demeanor hides a childhood trauma. The pair are both drawn to a mystical forest in Korea's countryside.

It follows the lives of employees at Incheon International Airport.