Chou Henshin Cosprayers VS Ankoku Uchuu Shougun

Overview

A short 10 minute film by the non-existant "Houchiku Movie Corporation" After destroying the dark castles and finally defeating the enemy, Scarlett leaves the group to continue on. While Koto and her friends are together, she meet up again with Scarlett expectantly. A new, powerful enemy is back and must be defeated at all costs, he is more powerful than all of the others... but it will take all of their powers to combine and work together as one...

Source: AniList