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’?
| Actor | Role |
|---|---|
 Sung Dong-ilHyeo Go-soo | Hyeo Go-soo |
 Song Sae-byukOh Dong-sik | Oh Dong-sik |
 Lee Byung-joonPresident Lee | President Lee |
 Kim Sung-ryungYe-ji | Ye-ji |
 Ko Chang-seokSung-cheol | Sung-cheol |
 Chang Hang-junCameo | Cameo |
 Jin Sun-kyuReporter | Reporter |
 Cha Seung-wonNot listed | Not listed |
 Hwang Seok-jeongNot listed | Not listed |
| KKim NinaNot listed | Not listed |
 Park Bo-kyungWoman | Woman |
 Kang SookOffice slogan woman | Office slogan woman |