Tobei Kirigakure, husband to Yayoi and father to Kotaro and Kasumi Kirigakure, masters a ninja dojo currently without pupils. He actively trains his son Kotaro in ninja arts, despite Kotaro's frequent avoidance of lessons. An early confrontation with the dark wizard Yaminorius III leads to Tobei's defeat; a curse transforms him into a dog. Known as Gonzales or Gon in this canine form, he remains cursed for the series' duration. His family believes he is away undergoing ninja training.

A secret ninja training chamber hidden beneath his doghouse reveals his ongoing dedication to the discipline. While transformed, he adopts the temporary alias "Shinobi Ganbar" and assumes the role of main pilot for the super robot Ganbaruger and its upgraded form, Great Ganbaruger. In this guise, he destroys a Devil Beast. Tobei eventually regains his human form in time to join the final battle against Yaminorius and the Demon World forces. This transformation back proves pivotal, enabling his direct involvement in the conflict's climax.