Yong Bi, Sang Woo, Ji Gong, and Doo Man are four 20-year-old friends. They take one last trip together to Pohang, before Sang Woo leaves to enlist in the military. At night, they drink on the beach and watch the night view of the sea. At that time, they see a woman being beaten by a man and run to save her.
(Source: AsianWiki)
