He was a thirteen-year-old street kid who killed countless people whose names he didn't even know.
He was his only friend, also displaced and taken away by the killer organization.
She was only ten years old, but she created a perfect murder scene for a doll she didn't like.
What kind of secrets are hidden behind the serial murders?
What are the intentions of the thirteen killers hiding in the dark that they don't know?
As the killers appear one by one, the secret seems to be coming to light.