Mu Ran, a lonely boy, was often bullied and humiliated by his classmates when he went to school because he had no father or mother. However, he has an experience that other classmates do not have. There is a homeless sexy girl Lin Zi living in his house. Lin Zi's gentleness and thoughtfulness attract Mu Ran, and Mu Ran falls in love with this girl. However, everything changed because of this girl, and Mu Ran experienced a lot. For the girl, he became a killer, but the girl's life experience is complicated and mysterious. Why did Mu Ran become the target of arrest in the city? A mysterious middle-aged man calls himself Master Mu Ran. Why does Mu Ran mutate into a monster? Escape to a deserted island... All of this also turned Mu Ran into a late-night avenger
Why did Mu Ran's life change because of a girl? Who is this girl? When Mu Ran finds out who killed her parents?