Oh Dong-sik is the completely rigid character who has always led a text-book life. Dong-sik is threatened by loan sharks when his mother signs up for a private loan in order to advance Dong-sik’s father’s promotion into the principal position. Dong-sik decides to become the best insurance seller in his newly transferred insurance sales team, but sales is a major challenge for the completely tactless and obstinate Dong-sik. Then one day, Dong-sik has a chance encounter with Hyugosoo, the legendary ‘master of tongue’ of insurance sales industry. Hyugosoo bends his rules and accepts Dong-sik as his pupil, and Dong-sik begins to learn Hyugosoo’s secrets of flattery after a great struggle. Will his teachings indeed reinvent Dong-sik into ‘Mr. Ass-Kisser’?