When Gururu was younger, he and his childhood friends wanted to take Chibi Keroro's base, but they were both soon beaten up by the chibi team and were forced to flee.

Throughout the series, he and Zurara would bully Keroro,Zeroro and Giroro without any of the teachers finding out.

In episode 162, while Giroro and Keroro were gonna go inside their secret base, Gururu and Zurara showed up with Zurara's pet Andromedian Husky, intending to beat the two up. UntilGaruru shows up to stop them, it is revealed that Gururu was expelled from The Keron Army Academy along with Zurara due to getting caught beating up Garuru.

He alter reappears in episode 285 as an adult criminal who steals planets. He reveals to Keroro that he and Zurara were always waiting until The Hinata's House was empty of both hisPlatoon and the humans which reside in the house. However, it is revealed that Aki Hinata is home, and the two criminals go under the illusion that they are some of Keroro's childhood friends. Despite being here to invade, the two criminals suddenly get attached to Aki, and they leave with smiles on their faces, even when they get caught by Poyan, they appear happy that they will be known as stars on Pekopon.