Sergeant of the Keroro Platoon. He has green skin and wears a yellow hat. There is a yellow star on his belly. He is indecisive, talkative, and cowardly, but his housekeeping skills are top-notch. He used to be strong. He loves plastic models.

Private Second Class of the Keroro Platoon. He has dark blue skin, wears a yellow hat, and has a beginner driver mark on his belly. He still has a tadpole tail. He is innocent and gentle, but he has a crazy side. He occasionally snaps. He admires Keroro.

Corporal of the Keroro Platoon. He has red skin, wears a red hat, and has a scar on his face. He is aggressive and meticulous. As such, he carries all sorts of weapons suited for any situation. He has a crush on Natsumi.

Major of the Keroro Platoon. He has yellow skin, an orange hat, and wears a headset. He has a red snail pattern on his belly and wears swirling glasses. He has a gloomy and dark personality. However, his computer skills are the best of the best. He is known for his 'ku-ku-ku' laugh.

Lance Corporal of the Keroro Platoon. He has light blue skin, wears a turban and a mask, and has a shuriken mark on his belly. He is a man of great common sense and possesses incredible ninja skills, but he often goes unnoticed due to his lack of presence.

An Angol girl. She usually has blonde hair, but her true form has short grey hair. She is very pure and kind, though a bit airheaded. She has a crush on Keroro and calls him 'Uncle'. Her weapon is a staff with a planet model, and her ultimate move is Armageddon, which can destroy Earth instantly. Currently, she is refusing to destroy Earth.

A human boy with short blue hair. Natsumi's younger brother. He is very kind, innocent, and oblivious. However, he is the scariest when he gets angry. His physical abilities are at the bottom tier.

A human girl with red pigtails. Fuyuki's older sister. She is usually sociable and affectionate, but she can be quite violent and especially hates it when Keroro causes trouble. She possesses incredibly strong physical abilities.

Fuyuki and Natsumi's mother. A human woman with a blue ponytail. She has a great physique and a great personality. She is fearless.

A human girl with short blue hair. She is usually very gentle, but when her split personality emerges, she becomes extremely eccentric. She likes Fuyuki Hinata—both her original and split personalities do.