The ranks followed in Keroro Gunso roughly follows those of the army ranks of the Japanese Empire during World War II.
Some ranks are shortened.
- Supreme Commander (最高司令官 Saikō Shireikan)
The unnamed Supreme Commander of the Keron Army and highest known authority of Keron itself that has been mentioned in the series.
- Marshal (元帥陸軍大将 Gensui Rikugun Taishō)
- General (陸軍大将 Rikugun Taishō)
- Lieutenant General (中将 Chūjō)
- Major General (少将 Shōshō)
- Colonel (大佐 Taisa)
Colonel, the unnamed leader of the invasion fleet, Keroro's direct superior. He is a recurring character in the manga and also appeared in the anime.
- Lieutenant Colonel (中佐 Chūsa)
- Major (少佐 Shōsa)
- Captain (大尉 Taii)
Captain Keroro, an artificially young Keroro in the anime, or a clone in the manga, receives this ranking due to being purified out of his impurities during the process. Jirara is also referenced as a captain. Keroro calls Aki Captain. Tamama also addresses himself captain in Episode 108.
- First Lieutenant (中尉 Chūi)
Garuru is a first lieutenant.
- Second Lieutenant (少尉 Shōi)
Onono is a Second Lieutenant
- Warrant Officer (准尉 Jun'i)
- Bariri is a warrant officer.
- Sergeant Major/Master Sergeant (曹長/曹長 Sōchō/taichou)
Kururu is a sergeant major. Note: Kururu's rank is higher than Keroro.
- Sergeant (軍曹 Gunsō)
Keroro is a sergeant.
- Corporal (伍長 Gochō)
Giroro is a corporal.
- Lance Corporal (兵長 Heichō)
- Private 1st Class/'Senior Private' (上等兵 Jōtōhei)
Taruru became a senior private. Note: Taruru's rank is higher than Tamama's rank.
- Private Second Class (二等兵 Nitōhei)
- Tamama is a private second class.
- Chief Medic (看護長 Kango-chō)
Pururu is a chief medic.
- New Recruit (新兵 Shinpei)
- Spy (偵 Onmitsu)
Gyororo is a spy.
- Seamstress (お針子 Ohariko)
Nuii is a seamstress.
- Private Third Class (三等兵 Santōhei)
- Karara was labeled a Private Third Class by Tamama.
- Captain (大尉 Taii)
Keroro calls Aki Captain. Tamama also addresses himself captain in Episode 108.
- Admiral (提督 Teitoku)
Keroro and the others call Akina Hinata admiral.
- Lowest Grand Sergeant (最低グランド軍曹 Saitei Gurando Gunsō)
Nobibi is a Lowest Grand Sergeant.
- Shogun (将軍 Shougun)
- (general) Keroro once declared himself a Shogun and Chibi Fuyuki has also labeled himself as one.
In Episode 107-A, Keroro explains about Group Rankings. The more people/Keronians you get in your group, the higher up in rank you'll get.
The Keron Army is the largest known army on the whole planet.
The Shurara Corps is the only known corps in the series.
There are a number of platoons shown in the series.