Planets/ Inhabitants Edit
In the series the planet that were introduced were only two and there are planets but the most detailed planets are:
A planet where Keronians (one of the main alien inhabitance in the series) exisit.
A inhabitance that was introduced at the 2nd movie of Sergent Keroro. They look similar to keronians.
The planet name is not mentioned in the manga/ anime. Salamander-like aliens. The most widely known is Sumomo.