A weak and sickly boy, Sung Woo-mun's condition worsens when he loses his mental capacities, owing to a painting gifted by a sage. He grows up as the 'village idiot', pitied by his own parents. But unbeknownst to everyone, his life is about to change soon, and a new destiny awaits him. When Sung Woo-mun turns 20, not only does he have an epiphany, but an undefeatable martial arts power begins to bloom inside the painting. What could all of this mean for Woo Mun? And what strange world awaits him?