"Katte ni Shinryakusha" (勝手に侵略者, "Aribitrarily invaders") by Naoya Ogawa & Mayuko Iwasa is used as the ending from episode 52 to 78.

Frog was released to Region 1 DVD in North America beginning with the first boxset containing episodes 52–65, on July 26, 2011, by Funimation Entertainment as Season 3 Vol.

In an attempt to hastily write a report on Earth children, Keroro impersonates himself as a teacher and spends the day with Fuyuki's and Momoka's class.

Keroro signs a deal to exchange two Earth humans for a ticket to a sports game on Keron with the Events Alien.

Natsumi and Giroro got a good, Fuyuki and Tamama didn't put that much heart into making theirs and Koyuki's riceball was too hard.

Momoka makes lunch for Fuyuki, and invites him to go with her into space on a shuttle so he can eat it with her while watching a comet as a ploy to seduce him.

Tired of Keroro's lazy ways, Giroro has Kururu invent a ray to turn the sergeant from slacker to stickler.

Natsumi accidentally gives chocolate meant for Saburo to 556, and calls upon the rest of More Peach Summer Snow to help get it back.