The Keroro Platoon finally stops pretending invasion is a joke. Earth is actually ending, and four amphibious idiots are the only ones who notice, let alone care enough to do something about it. The largest-scale battle in franchise history proves that even the laziest comedy show can earn its apocalypse.

The Keroro Platoon has settled into a lazy routine on Earth, treating their invasion as if it hardly matters. That changes when a string of bizarre phenomena breaks out across the country. Sensing a crisis, the frog soldiers rise to action, putting their pride as invaders on the line. Wherever they go, they run into mysterious symbols whose meaning they must uncover. What follows is billed as the biggest battle in Sgt. Frog history, set in the Reiwa era. The sci-fi comedy film is a new project marking the franchise's 20th anniversary.