From Tokyopop:
Daisuke Aurora works with the special division of peacekeepers in the city of Jewde, one of the largest cities on the planet. He and his android partner, Heat Guy J, team up to make sure that anything illegal stays off the streets and out of circulation.
However, their presence doesn't sit too well with the local mob leader--a ruthless, unbalanced, well-armed son of the late Don, who is out to prove that he is not too young to take over the family business. In the city that never sleeps, will Daisuke and Heat Guy J end up sleeping with the fishes?

Wiki:
Coinciding with the anime series in 2002, a manga version of Heat Guy J was released. It was eventually distributed in the U.S. by TOKYOPOP in 2005. It was written and drawn by Chiaki Ogishima. While the main characters and general setup were similar to the anime, the manga has its own unique storyline and supporting characters. There is only one volume in the series, and it includes several pages of bonus material related to the show.