Medical Student Kang Ma Roo takes the blame for a murder he did not commit and is sentenced to five years of imprisonment. Once released, he is a changed man and starts to use ladies for his own benefit.

Seo Eun Gi feels unusually indebted to Kang Ma Roo when he is risking his life for a precious item of her. Though she does not understand Ma roo at all, she becomes very curious about him.