Neptune is Beyond My Closet - That Crazy Age of the Dinosaurs

Sinopsis

Ataru, Shinobu and Lum’s Stormtroopers wind up in Neptune through a portal discovered in Ataru’s closet where they are greeted by Lum’s friend Oyuki. While in the air, Lum, Ataru, Ten and Kintaro accidentally wind up back to the dinosaur age.