Aki Hinata's mother and the maternal grandmother of Natsumi and Fuyuki. To Keroro, she is the final boss. While her name is Akina Hinata, Keroro refers to her as "The General" because he perceives her as the ultimate authority of the household. Despite being a typical rural grandmother, she possesses an incredible level of adaptability, never showing surprise at urban culture, modern machinery, or even alien technology. She adjusts to them instantly. -> (In their first meeting, where she secretly helped Keroro, Tamama, and Giroro, the group saluted her from the trunk of a car upon realizing she was Aki's mother. Instead of being shocked, she simply smiled and saluted back, saying they must be the new family members.) Tamama calls her Grandma comfortably. (Keroro and Dororo address her as "General.")

13 years old. Likes: Keroro, ghosts, aliens, and all things occult. Dislikes: Exercise, insects. Natsumi's younger brother. Bright, kind, and very curious. He calls Keroro "Sergeant" and Giroro "Corporal," addressing them by their ranks. (This includes Kururu, but excludes Tamama and Dororo.) Uses informal speech. Kind-hearted with maxed-out social skills.

14 years old. Usually social, affectionate, and kind, but becomes violent whenever Keroro causes trouble (hitting, kicking, tying him up, etc.). Likes: Exercise. Dislikes: Keroro (because he only picks weird things to do, though they share a love-hate bond), mollusks, ghosts. She is relatively kind to Giroro as long as he doesn't cause trouble. Has a crush on Sabin. Calls Keroro "Stupid Frog."

Age: Estimated mid-30s. Occupation: Manga Editor. She recoils at the sight of vertebrates as if she's seen a monster, yet strangely likes creepy-crawly, slimy creatures like bugs. Her tastes are quite eccentric. She is a charming, capable, and tough woman, as well as a great mother. She is the reason the Hinata children grew up well despite their father's absence. Her athletic ability is excellent (Natsumi clearly inherited it). When she was turned back into a student by Kururu's gadget, her athleticism far surpassed Natsumi's. She bears a strong resemblance to Fuyuki.

14 years old. Kind, polite, and extremely pure-hearted. Likes: Natsumi (as a friend), Dororo (as a fellow ninja; she trusts him deeply, and Dororo considers her his savior and friend). Occupation: Ninja. A ninja girl who appeared alongside Dororo. She is the savior who rescued Dororo from a trap (though she was the one who set the trap...). They currently live together like family. Despite Dororo's "lack of presence" setting, Koyuki always acknowledges him. She works with Dororo to defeat hostile aliens. She lived in a secluded ninja village, but when the village was disbanded because ninjas were no longer needed, she entered general society. Being new to social life, she occasionally causes odd troubles. Except when commuting with Natsumi, she usually travels by jumping across rooftops.

Sergeant. Childhood friends with Giroro and Dororo. He unintentionally picks on Dororo but considers him a precious friend. As a Sergeant, he speaks informally to everyone in the platoon, but uses polite honorifics with humans. Lives at the Hinata residence. Refers to human females as "Lady (Name)" and human males as "Master (Name)." Uses polite speech with humans, ending sentences with "-de arimasu." Human Partner: Fuyuki Hinata

Corporal. Childhood friends with Keroro and Dororo. Tsundere. Has a crush on Natsumi Hinata, so he stammers or freezes up in front of her. Finds Keroro pathetic for neglecting the invasion of Pekopon. Obsessively diligent. Uses informal speech. Human Partner: Natsumi Hinata

Private Second Class. Hides a violent and aggressive side behind a cute and bright exterior. Follows everything Keroro says (because he loves Keroro). Youngest in the platoon. Uses polite speech. Addresses others as "Sergeant Keroro," "Corporal Giroro," etc. Human Partner: Momoka Nishizawa

Major. Poor physical stamina. Gloomy and eccentric. Extremely intelligent. Laughs with a distinct "Ku-ku-ku." Uses informal speech. Human Partner: Sabin

Lance Corporal. Kind and polite, but cries whenever Keroro forgets about him. Former member of the X-1 unit. An assassin. His personality flips completely when he gets behind a steering wheel. Childhood friends with Keroro and Giroro. Wears a mask. (He once took it off by request, but everyone missed the moment, so no one has seen his face.) Uses archaic/formal ninja speech (Gozaimasu style). Lacks presence. Ninja. Human Partner: Koyuki Azumaya Calls human females "Lady (Name)" and human males "Master (Name)."