Giroro is the corporal of the Keroro Platoon and their weapons expert. His main body is red, while his headgear is maroon with a yellow skull in the middle. He is the only member of the platoon who doesn't wear a symbol in his belly. Instead, he wears a belt with a rectangular buckle diagonally across his body. However, when he was a tadpole, he had a skull symbol on his belly. His afro, which is rarely seen, is blonde. He first appears on the second volume of the manga, chapter 11, and in the third episode of the anime.
Giroro is in love with Natsumi Hinata, something everyone but Natsumi seems to know, since she defeated all his traps he set when he arrived to the Hinata house. That is why he would attack anyone who harms her and also the reason why he views Mutsumi Saburo as a strong romantic rival, but also Koyuki, who has a crush on her. Ever since his first encounter with the Hinatas, Giroro has been living in a tent in their backyard, where he roasts sweets potatoes he sometimes shares with Natsumi and obsessively cleans his weapons. The buckle of his belt hides his treasure, a photo of Natsumi.
Giroro is grumpy, impatient, and provocative, so he has a short temper, and he is often irritated by the laid-back and unfocused attitude towards the invasion of the other members of the Platoon, specially Keroro. He appears to be gruff, but he is an honorable frog with a good heart. He often shares his tent with a whiteish pink female cat whom he rescued from the rain called "Neko-chan" ("Miss Furbottom" in the English FUNimation dub). Unknowingly to him, the cat is in love with Giroro. He lacks any other hobby apart from his weapons and he is terrified of ghosts and sea cucumbers. He also cannot drink more than a drop of alcohol without passing out.
Despite being absolutely dedicated to the call of duty, Giroro is often used as comic relief throughout the series. Most often he is crushed by something dropped from Natsumi's window, or a falling object from space, usually containing an alien of some sort (or Karara). Other times his romantic dilemma with Natsumi is what leaves him uncharacteristically clumsy and blundering. His feelings toward her are also often used by other characters to get him to agree to something, by saying that she will like it. That's why sometimes, even if the invasion plan fails, he is seen with a dopey happy grin on his face if the outcome had made Natsumi happy.
Giroro is the one who suffers more misfortunes of the entire platoon, either by accident, bad luck or by being deliberately chosen by Keroro, Tamama and/or Kururu as guinea pig. Among others, Giroro has been forcefully attached to a machine to be used as a living "fear-meter" during an horror story competition, merged together with Keroro, became merged with Natsumi's right hand due to a failed experiment, transformed into a liquid form and even he also became human for a short time, with blond hair and tan skin in episode 196, Return of GeroGero 30 minutes. One of these accidents happened during an experiment to bring out the strongest personality from within, where Giroro mistakenly set off the "energy bullet" that was originally meant for Keroro. He split into seven characters (including the original), one for each physical manifestation of his personality.
- Sometimes when Giroro becomes angry, his eyes color changes from black to grayish-black.
- Giroro has an older brother named Garuru, who is the liteutant of the Garuru Platoon and has a sibling rival towards each-other.
- When Giroro transformed into a human thanks to Kururu's gun, he started to have blonde hair, reflecting his afro color.