With just one punch, a foreign merchant named Ronny (Mahbub Alam) knocks out In-Ho (Yu Jun-Sang) during one of his Taekwondo training classes. In-Ho then goes to find Ronny to recover his dignity. However, what comes next is separation from his wife and being imprisoned..
| Actor | Role |
|---|---|
 Yu Jun-sangNot listed | Not listed |
 Park Young-seoNot listed | Not listed |
| CChoi Hee-wonJung-a | Jung-a |
| RRobin ShiekNot listed | Not listed |
 Mahbub AlamRonny | Ronny |
 Park Gil-suNot listed | Not listed |
 Ryu Ui-hyunNot listed | Not listed |