Whenever there are many people in an area, violence is always present. Gangs rise up, claiming territories which they they fight to protect and expand. Killers find their places amongst the innocent in order to remain hidden. Disappearances are far from uncommon. These things are all to be expected when there is a high population in a small area. No one expects anything different when they go to Tokyo, but they're wrong. Something on the streets of the city is taking out gangs, police, and anyone else who runs into it. The only problem is that no one has seen it and survived, so there isn't anything the people can be warned to look out for. Instead, everyone knows to avoid the silent killer but not what that title belongs to.