Keroro Gunso (ケロロ軍曹, Keroro Gunsou, lit. Sergeant Keroro) is a manga series by Mine Yoshizaki It was serialized into a TV anime series with the same name directed by Junichi Sato.

Keroro Gunso is a series about a group of aliens led by Sergeant Keroro that is tasked by the army of Planet Keron to prepare Earth for their invasion. However, the platoon of five ends up being friends with humans in Inner Tokyo, and their plans of invasion stuck up indefinitely.

The series takes its comedy from a combination of wordplay (particularly puns and homophones), physical humor, situational humor, and numerous pop culture references (especially to Gundam, Space Battleship Yamato and Neon Genesis Evangelion). Various anime, games, manga, and other aspects of pop culture are parodied/referenced throughout the series as a bonus to older viewers. Both the manga and the anime are laden with pop-culture references, and even in the same story the references often vary wildly.

Characters

Sergeant Keroro (ケロロ軍曹, Keroro Gunsou) Voiced by: Kumiko Watanabe

Sergeant Keroro is the hyperactive and manipulative leader of the Keroro Platoon. The antihero of the series, the platoon's plans almost always fail because of him. When it's not his turn doing the Hinata family's household chores, he would spend his time making Gundam models, watching anime, sleeping, or other stuff instead of coming up with a plan to conquer Pekopon (Earth).

Fuyuki Hinata (日向冬樹, Hinata Fuyuki) Voiced by: Tomoko Kawakami

Fuyuki Hinata is what makes an average Japanese teen except for one thing: he's obssessed with the occult and paranormal. This obsession, however, made them discover Keroro in his hiding place. Now, Fuyuki and Keroro are very close friends. Whenever Fuyuki recalls their friendship, Keroro stops with whatever plan he has come up with. Fuyuki also has low stamina and therefore low interest in sports and does not know how to swim.

Natsumi Hinata (日向夏美, Hinata Natsumi) Voiced by: Chiwa Saito

Natsumi Hinata is the hot-blooded girl who commands around the house. Keroro works under Natsumi's demands while calling him stupid frog. The opposite of his brother Fuyuki, Natsumi is gifted with the stamina and one of the best in Kissho Academy. She is especially sensitive to whatever invasion plans the Keroro Platoon comes up with.

Private Second Class Tamama (タママ二等兵, Tamama Nitouhei) Voiced by: Etsuko Kozakura

Tamama is the cute character in the Keroro Platoon and he loves Keroro. Tamama's mood can change very quickly, especially when Keroro gets his attention on something or someone else. As being the cute character, he is always seen eating cake, cola or chips.

Corporal Giroro (ギロロ伍長, Giroro Gochou) Voiced by: Jōji Nakata

Giroro is the serious character in the platoon. He is the one who always reminds Keroro about the invasion. Giroro is also good at guns, to the extent that he always makes them shiny. Aside from guns, he is also madly in love with Natsumi. When abused, this fact can affect him greatly.

Sergeant Major Kururu (クルル曹長, Kururu Souchou) Voiced by: Takehito Koyasu

The resident brains, Kururu is the intelligence officer of the platoon. His downside is his bad personality, but he makes effective inventions, some with interesting effects. His knowledge in hacking is also useful at times. He becomes uncomfortable when someone with a pure heart stares at him.

Lance Corporal Dororo (ドロロ兵長, Lance Corporal Dororo) Voiced by: Takeshi Kusao

Zeroro is the platoon's ninja assassin. Zeroro changed his name to Dororo when he came to live with Koyuki. Zeroro has always been friends together with Keroro and Giroro, until the becoming of the Keroro Platoon, despite Keroro using Dororo for various bad situations. As such, when he is reminded of one of those, his trauma switch turns on and becomes useless for the next few moments.

Momoka Nishizawa (西澤桃華, Nishizawa Momoka) Voiced by: Haruna Ikezawa

Momoka Nishizawa is the rich daughter of the owner of the big Nishizawa corporation. Momoka discovers Tamama, who now lives with her. She is in love with the average Fuyuki, and does everything to get him. She has a split-personality, the more courageous of which appears when she is angered by Keroro or some other factor.

Angol Mois (アンゴル＝モア, Angoru Moa) Voiced by: Mamiko Noto

Angol Mois is a planet destroyer from Angol destined to destroy Earth. Angol Mois and Keroro had been friends for a long time such that Angol Mois regards Keroro her 'uncle', and they can get too close to each other, much to the jealousy of Tamama. She transforms into a human form (based on a girl named Asami) for disguise.

Koyuki Azumaya (東谷小雪, Azumaya Koyuki) Voiced by: Ryo Hirohashi

Koyuki Azumaya is a ninja who lives with and is a friend of Dororo. She has always lived with the ways of the ninja, and has therefore trouble adapting to city life. She becomes in love with city girl Natsumi who is also a student of Kissho Academy.

Mutsumi Saburo (サブロー睦実, Saburō Mutsumi) Voiced by: Akira Ishida

Saburo is also a student of Kissho Academy, but skips school a lot because of his extremely high IQ. He becomes friends with Kururu, who shares the same trait. He also hosts his own radio show as 623 (pronounced Mutsumi). Natsumi is in love with Saburo, and also consequently listens to his radio show.

Aki Hinata (日向秋, Hinata Aki) Voiced by: Akiko Hiramatsu

Aki is the buxom mother of Fuyuki and Natsumi. She calls the Keronians by their short name plus -chan. Aki is a very busy manga editor, although tries to find time with her children.

http://keroro.wikia.com/wiki/Keroro_Gunso