Sergeant Frog

Sgt. Frog, known in Japan as, is a manga series by Mine Yoshizaki. It was later serialized into a TV anime series directed by Junichi Sato. Both the anime and manga are comedies that follow the attempts of a platoon of frog-like alien invaders to conquer Earth. Sergeant Keroro, the titular character, is the leader of the platoon, but is at the mercy of a human family of three after he is captured while trying to hide in one of the family member's bedrooms. In both the manga and anime, Keroro is forced to do meaningless chores and errands for the family after his army abandons his platoon on Earth.

The series takes its comedy from a combination of wordplay (particularly puns and homophones), physical humor, situational irony, breaking of the fourth wall, and numerous pop culture references (especially to Gundam, Kamen Rider, Space Battleship Yamato, Dragon Ball, and Neon Genesis Evangelion and many others). 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. The anime does not explicitly refer to Evangelion or other animations to which Bandai does not hold the copyrights, but only recreates the "feel" of famous scenes from these anime. The anime is much more detailed and direct in its Gundam references, however, since Bandai does hold rights to the Gundam franchise.

Plot
Both the manga and the anime focus on the steadily deteriorating conditions of the Keroro Platoon, a group of five two feet-tall, frog-like aliens from Planet Keron of the Gamma Planetary System. The platoon’s mission is to invade and conquer Earth (known to the aliens as “Pekopon”), but fail miserably at each attempt. Sergeant Keroro, the leader of the platoon, is easily distracted, and would rather spend his time making plastic Gundam models than invade Earth. Aside from Keroro, there are four other members of the Keroro Platoon: innocent yet violent Private Second Class Tamama; bellicose and serious but caring Coporal Giroro; intelligent but trouble making Sergeant Major Kururu; and stealthy but melancholic Lance Coporal Dororo.

The largest obstacle in the way of their mission is the Hinata Family, whom must take care of the Keroro Platoon due to the Keron Army deserting the latter on Earth. Keroro is kept busy with manual labor and constant abuse, primarily from the family daughter Natsumi. The other four members of the platoon also find themselves in the care of a human, who are all tied to the Hinatas in some way throughout the events in the anime and manga.