James Kennedy was known to be the deadliest Hitman to ever lived. And someone with constant trust isues due to the number of betrayals he had. His only mistake was trusting one client, who wiped him out from existence, literally. He was then given another chance to live in a magical world in the body of a girl, and wouldn't mind to live a normal life if that girl wasn't threaten like she could be the most powerful villain despite not being able to do magic. Armed with her past abilities and experience, the newly named Ken fight her own battle. The battle against the light that want to end her, literally, and against the darkness that consider her as their ultimate weapon.