Hee-yeon, a girl crushed by debt in the rundown neighborhood of Changseong, is on the verge of being dragged to a red-light district. She is saved by Moo-gil, a gangster who appeared like the wind.

“I'm good at studying. I can repay my debt without working in the lower town.”
“You're surprisingly impressive for someone like you. Start coming to work here tomorrow.”

As she spends time by Moo-gil's side, Hee-yeon gradually becomes more immersed in his tenderness. But the moment he realized her feelings, Moo-gil suddenly turned cold, unlike before...

“Just call me ‘mister’. I’m not your boss when you’re swearing.”