Now 18 years old and living on Earth in a luxurious mansion, Banjō fights against the Meganoids and their leader, Don Zauser and his second in command Koros, with the aid of his faithful butler Garrison, his two gorgeous companions, Reika and Beauty, and an orphan boy named Topo.

The suave nature of the hero, Banjō Haran, was a direct attempt at capturing some of the spirit of the James Bond films, which can be seen in the fact almost as much action takes place with Banjo, Reika Sanjō (ex-Interpol agent) and Beautiful Tachibana (also called "Beauty") playing superspies as Banjō fighting against Meganoid robots in Daitarn 3.

Other important characters were Garrison Tokida, Banjo's trusted butler, and Toppo, a comic relief-character who gets rescued from a Meganoid-hijacked city block in episode 2, and then stays with Banjō and company for no apparent reason.

One of the most notable appearances was in Super Robot Wars Z2 Saisei-hen where he manages to prevent the death of Shirley Fenette from Code Geass should the player gather enough "Zero points" throughout the game.

In Super Robot Wars V, Banjo reveals that Hokushin, the main villain of Martian Successor Nadesico: Prince of Darkness, is the last living Meganoid.