Tae Ho and Sang Goo are two men who constantly fought at work and hates each other even more now that they’re both the heads of rival companies. When their children Do Hee and Young Joon get married, the bickering fathers are forced to become in-laws.

He is the star of "The Age of Wild Men" that brought Kim Doo-han into Jong-ro. No one is able to hold onto their lives before Dual Wielding Swordsman's fists, which are deadlier than a knife. The legend of Joseon's greatest Dual Wielding Swordsman begins.