From MangaHelpers:
In a land far away, the evil demon lord ruled with absolute power and cruelty. But a group of heroes combined their strengths and conquered obstacles to finally reach the demon lord in a final fight. When the sorcerer cast the imprisonment spell that was supposed to trap the demon lord, it also dragged all the heroes into a different dimension.
The demon lord, who looks and acts like a teenage girl, has lost her legendary powers and is forced to rely on the heroes to find a way to escape the prison. The sorcerer, who is leading the search on how to break out of the spell, can’t help but to tease the now powerless, bratty and emotional demon lord that once was a threat to the entire world.