Fuyuki Hinata Friends

Fuyuki and Natsumi's mother. Aki is a manga editor who decided to base the main character of her latest manga on Keroro.

A undead being / toy doll who feasts on aliens to gain humanity. She has a crush on Fuyuki Hinata due to his liking of the supernatural.

The "Queen of Terror" who was sent to planet Earth to arrive in July 1999 for Earth's destruction, as predicted by Nostradamus but arrived 500 years too early and takes a nap in orbit, until she wakes up 5 years late. Now she assists Keroro in conquering the planet.

Corporal of the Keroro Platoon and their weapons expert. Giroro only weakness is his love of Natsumi Hinata, something everyone but Natsumi seems to know. Giroro is so protective of Natsumi that he would attack anyone who harms her.

The main protagonist of the Sgt. Frog (Keroro Gunsou) Series. Keroro is a Alien frog sent from his home planet to take over Pekopon (what Aliens call Earth). But instead Keroro would rather build Gundam Models than accomplishing his task.

Kitten is a young cat that Giroro found and has since lived with him in his tent.

A kunoichi who falls in love with Natsumi and is close friends with Dororo

The head of communications in the Keroro Platoon. Despite he is of a higher rank than Keroro, he is not the leader of the Platoon due to his unpleasant and unnerving demeanor. Kululu's expertise lies in his high-level technological prowess, including hacking and inventing.

The multi-billonaire one-sided lover and classmate of Fuyuki Hinata. Despite being outgoing in everything else, Momoka is really shy when it comes to Fuyuki, and she is unable to confess her feelings to him. Momoka also has a split personality that surfaces when she is angry or her plans fail.

The older sister of Fuyuki and the one in charge of the Hinata house when their mother is not home. She is very strict on Keroro and always doubts of his intentions, physically abusing him on several occasions and treating him as a slave.

The adoptive 'father' of Alisa Southerncross. Nevula commonly takes the shape of the cat ears on top of Alisa's head. He desires to turn Alisa into a human and will do anything to accomplice this task.