Three nights before enlisting, Seung-wook decides to leave his mark since he can't avoid the military so he flirts with everyone. However, his school senior So-yoon nor his blind date Il-hong will fall for him. The night before he leaves for the army, Seung-wook decides he's going to see some action with the two girls. The project of 'leaving a mark' starts now.
| Actor | Role |
|---|---|
 Kim Seung-wookSeung-wook | Seung-wook |
 Han Seol-hwaSo-yoon | So-yoon |
 Heo Yoon-jooIl-hong | Il-hong |
 Kim Sang-cheol-IJoon-gi | Joon-gi |
 Lim Hyeong-soonSe-joon | Se-joon |
 Moon Yoo-seongYang-woo | Yang-woo |
| KKim Hye-jinSe-kyung [Yang-woo's Girlfriend] | Se-kyung [Yang-woo's Girlfriend] |
 Min Joon[Building Man] | [Building Man] |
 Lee Yoo-hee[Building Woman] | [Building Woman] |
 Lee Jae-seok[Military Official] | [Military Official] |
 Baek Se-ri[Black Horse] | [Black Horse] |
 Yang Geun-seok[KATUSA Soldier] | [KATUSA Soldier] |