Onipan! Season 1 Episode 21 Momo Battle Royale! Part 1 ( Air Date 2022-05-09 ) Genre Animation, Comedy, Sci-Fi & Fantasy category. Overview "The Momo Battle Royale is about to begin! …too bad no one knows what a Momo Battle Royale is. Time for Momo, descendant of the #1 Oni-Enemy, to take to the stage and explain!".