well recently ive been hearing that but before that i was told he got it in the war on keron i am going to do some research here then i will report back to you
its okay i do know that he went to military school as a child and that he had a secret base thingy and he was friends with dororo(or back then zeroro) keroro and pururu and giroro was pretty much the only one that was generaly nice to zeroro as a child unlike some keronians we know. and he was in a war on his home planet which he has a scar from and his scar and his belt are all he has to remember his fallen friends from that war and they are priceless to him.
Oh he also befriended a hobo once as a child too. lolz
i just wanted to say that i know pretty much everything about giroro so i am willing to answer any question that you have to ask about him so fill free to ask.
human? how do you know im human or ever was one?
jk i am human i don’t realy know what my earliest human memory was