Dear M is a campus romance about Business Student , a computer science student, and their group of friends at a university that get caught up in the chaos of a mysterious online community poster known as M. Joo Ah wonders about the mysterious M and falls for another classmate, Min Ho and Joo Ah are longtime best friend, but he slowly develops feelings for her.

Ji Min and Ha Neul are popular couple on campus but their perfect relationship faces chanllenges and Obstacles.

Watch to find out what happened to Ma Joo Ah and Cha Min Ho's friendship, JinMin and Ha Neul's relationship and finally if our neatfreak Mok Jin still stays single? And finally WHO is M?