In the far future, there are seven cities located on a planet. Each of them are independent from each other and formed countries because there is no other life on the planet other than those seven cities.
The story takes place in one of the cities called Judo. Judo is a floating artificial city build on the sea roughly 30km on its diameter. City administration tower located in the center with large skyscraper residences around it. The south area of this city is a slum where most of crimes take place.
Speaking of crime, Daisuke Aurora is the city safety control officer. His job is to preceive any incidents and prevent them before they happened. On the surface he looks as a person with sense of justice and humanity, however he's actually taking out crimes because of his father, a politician, who was assassinated by terrorists. Luckily, he has a partner, an android called Jay (R-JAJA000106).