Cha Sang Doo and Chae Eun Hwan were childhood friends until tragedy struck when Sang Doo accidentally killed someone while defending Eun Hwan's family belongings. After serving prison time, he discovers Eun Hwan and his family have disappeared. Years later, Sang Doo becomes a gigolo to support his sick daughter and unexpectedly reunites with Eun Hwan, now a math teacher. To win her back, he enrolls as a student in her class,
