One Way Trip: Four best friends, Yong-bi, Ji-gong, Sang-woo and Doo-man who just turned twenty and just came of age took the road to Pohang, a small city near the beach—since one of the friends, Sang-woo, is enlisting in the marine corps the day after. On the last day before Sang-woo goes off to the army, a life-changing incident dawns in front of them. The four best friends now face a situation beyond their control, and are forced through an irrevocable day.