In the year of 2004, chaos ensues when a peculiar frog-like extraterrestrial race fills the sky with UFOs--as 12-year-old Fuyuki Hinata dreams. As luck would have it, Sergeant Keroro, commander of an advance unit for the Keronian intrusion of Pekopon, or Earth, initiates his assignment by attacking Fuyuki's home. Upon rendering the boy and his sister helpless, Keroro devises a plan to rendezvous with his fellow warriors and return to the mother ship to restore their priceless invasion apparatus, the Kero Ball. Lamentably, he receives news that headquarters has deserted his squad's extraction due to an extraordinary predicament that compelled other Keronians to retreat. Therefore, Keroro must remain at the Hinata residence alongside the amiable dreamer Fuyuki, his athletic and irritable sister Natsumi, and their diligent and attractive mother Aki. With no timeline for departure, Keroro and his team spend their days scheming global rule, thwarted repeatedly by unexpected obstacles. Nevertheless, as they coexist among humans, they learn to treat them as companions and confidants, forming amusing yet meaningful bonds that give value to their lives on Earth.