Maronians are an alien species from the Keroro Gunso series. Maronian used to be invaders a long time ago, but has stopped. Keronians learn about them in history class. Maronians take over planets by marrying a female native then flooding the planet until it is fully covered in water. Currently, the only Maronians known are Meru and Maru, appearing on the second Keroro Gunso Super Movie, and Miroro, introduced volume 20 of the manga.