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 joins forces with heavy hitting sadistic gangster Buppa of Buppa Town. With Buppa's support, Merra aims to initiate a gang war between the Wu-Ronz and the Musashino Saru, and in a confrontation between the two attempts to kill popular member of the Musashino Saru - Kai. By mistake, Merra instead kills Kai's friend Tera (a Musashino Saru member beloved by members of all Tribes since before their formation). This leads to the joining of forces between all of the Tokyo Tribes in an all out war against Merra and Buppa's forces.

Set in the near future in Tokyo, Japan. The evil terrorist organization Galactor has declared war on the world. The group possesses more advanced technology than governments and occupies over half of the planet. Dr. Kozaburo Nambu of the International Science Organization gathers together 5 superhero ninja agents, known collectively as Gatchaman, to stop Galactor.