Sometime in the near future the ocean city-state known as Judoh, has outlawed all androids in the city. Unfortunately the mafia doesn't like that law. In order to tackle the problem of mafia type actions Judoh's City Safe Management Agency created the Special Forces Unit separate to the usual police force; the job of the Special Forces Unit is to deal with possible crimes and prevent them from happening. Since the Special Forces Unit might be dealing with hi-tech androids the City Safe Management Agency created J: the only legal android to be allowed in the city. Judoh has a bad history with android so they weren't going to just let J go free in the city; instead he is partnered up with Daisuke Aurora: an Officer of the Special Forces Unit.
The group that runs most of the illegal activities in the city is headed by power families. Each family trying to scratch out the other, the main family in this anime is the Leonelli family. After Lorenzeo Leonelli died his son Claire Leonelli became the head of the organization. Claire despises the Special Forces Unit and becomes Daisuke's rival early on. With a group of thugs and countless other adversaries Daisuke and J have their hands full. Claire and his countless forces becomes the main target of the Special Forces Unit. Since the mafia is a underground organization, Daisuke has to connect the dots and connect them to Claire, which isn't easy since Claire knows how to cover his tracks