Sgt. Frog Season 4 Episode 164 Keroro: Nyororo Extinction, Sir? / Lavie's Going to Get Married, Sir!

While fleeing from the annual rainy season Nyororo, Keroro and crew head back billions of years into the past, where they have a chance to wipe out the Nyororo before they come into existence! Then 556 is upset when his little sister, Lavie, is about to get married, but the romantic Natsumi enlists Keroro's help to convince him to accept it!