When Ji Won Young's direct superior at work is fired due to a corruption scandal, Won Young - in spite of being innocent of any wrongdoing - finds himself unceremoniously discharged from the company as well. Desperate to get his job back, Won Young tries to curry favor by tracking down the chairman's favorite artist. He finds the missing man running a pottery shop in a remote town, but it's clear that Yoon Tae Joon has no desire to be found. Won Young decides to hang around town and secretly report whatever he can learn about Tae Joon's self-imposed exile; but when feelings begin to develop between the two, Won Young starts to question his sexuality, his motivations, and whether he even wants to go back to his old life in Seoul. But what will happen when Tae Joon learns Won Young has been spying on him this entire time?

“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.

Nam Han Joon is a former criminal profiler, who now works as a fraudster. For his scams, he disguises himself as a fortune teller and runs the fortune teller shop Minamdang. He attracts customers with his attractive physical appearance and smooth talking skills. He scams his customers for money, but he also gets involved in their cases and helps solve them. He even provides customer service for his clients. Nam Han Joon's partners are Soo Cheol and Nam Hye Joon. Soo Cheol runs a private detective agency and Nam Hye Joon is Nam Han Joon’s younger sister. She is an elite hacker. Han Jae Hee has worked as a detective for 3 years. She is enthusiastic about her job and tries to follow a righteous path. Somehow, Han Jae Hee gets involved with Nam Han Joon.

The Moorim School isn't focused solely on high academic scores. The school teaches its students virtues including honesty, faith, sacrifice and communication. The teachers and students at the school come from different countries and each have their own stories.