El detective privado Ryo Saeba —experto francotirador y mujeriego sin remedio— acepta, a regañadientes, aliarse con la hermana de su compañero para investigar su muerte.

In an alternate Japan, territorial street gangs form opposing factions collectively known as the Tokyo Tribes. Merra, leader of the Wu-Ronz tribe of Bukuro crosses the line to conquer all of Tokyo. The war begins.