I'm not him! He's the criminal, I'm the mistake!

Hyun-jun, an ordinary postman, is mistakenly arrested as a wanted criminal due to his identical appearance to fugitive Choi Cheol-gu. While struggling to prove his innocence, the real Cheol-gu escapes prison and flees to Taiwan. When Hyun-jun travels there on a reward trip, he is once again mistaken for the criminal and even kidnapped, only to be rescued by tough detective Woo-hee and her partner. As repeated mix-ups lead to comedic chaos, Hyun-jun and Woo-hee grow closer and ultimately team up to catch the real fugitive together.