Keroro's incompetence is the entire engine of the plot. A frog alien soldier literally leans on a button and accidentally triggers an ancient doomsday device, and the movie commits completely to the idea that this is the funniest possible way for a catastrophe to begin. You watch a ragtag squad of misfits sprint away from their own disaster, which is exactly what a Keroro fan signed up for.

Fuyuki Hinata and the Keroro Platoon are exploring an abandoned temple in Machu Picchu, Peru, when Keroro sets off a trap by accident. The group stumbles onto a secret room with a big blue crystal at its center, set on a stand that holds a key. Keroro leans on the key, a strange machine springs to life, and the whole temple begins to shake. As everyone runs for the exit, Keroro drops his Kero Ball, and Fuyuki briefly spots a young woman who seems to glow. After they get out, the girl, now bearing wings of light, watches them leave, while something starts to grow inside the crystal. The film is a sci-fi comedy with mecha elements.