Sgt. Frog Episode 102: The Keroro Platoon - Pekopon!! Impending Destruction of a Loved Planet!!
Episode 102 of 358 of Sgt. Frog, aired March 24, 2006, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Earth is falling to the invaders, and the Keroro Platoon is helpless to stop them. Even though the Galulu Platoon is supposed to be another part of their own army, the Keroro Platoon don`t really want the Earth to be invaded, and they`re now fighting to save it. But compared to the Galulu Platoon, they`re hopelessly outmatched, and all seems lost. Source: crunchyroll