Gangu is the invention of Dr. Ein, best friend of Bongo and tutor for White Bomber. Gangu is chatty, self-centered, annoying and is also one of the members of the Jetters. Bongo upgrades Gangu numerous times into random objects to help with their missions and daily life; Gangu dislikes this and even wished that Bongo wouldn't upgrade him.
Gangu is portrayed as a humorous character throughout the series. He would occasionally break the fourth wall.
Bongo often tinkers with Gangu, usually modifying him to be useful ("useful") in various ways.
Gangu is White Bomber's tutor.
Dr. Ein is the creator of Gangu. In one episode, Ein once played an April Fool's joke (what he didn't know is that it was April 2nd) saying that when he created Gangu he fell in love with one of Bagura's inventions.