1592 - Joseon: In those days, it was common for the rich to hire the poor to do their hard and dangerous mandatory military duties. They were called 'proxy soldiers'. A veteran proxy soldier TOW and his comrades are deployed to the south, where the Japanese has invaded. The King of Joseon has decided to seek asylum in China, and as he flees, he orders his young son -18-year-old Prince GWANGHAE- to take over the country's military command. Vulnerable Gwanghae is devastated, but with Tow's help, he is ready to fight in that harsh reality.