"It seems I was reincarnated as something that isn't human into a different world... something that drains my SAN points when I look into the mirror... and as the child of the demon lord no less. A demon lord who eats humans. And makes me eat humans, too.
This is a dream, right?
Well, I'll enjoy this craziness as long as it lasts. Maybe it'll make for a good story at school next morning. It's really a dream, right? Right?"
A simple, albeit tomboyish, Japanese high school girl is reincarnated as a monster made up of tentacles, in a world of sword and magic, and beings that drain one's sanity simply by existing. She is thrown out into the wilderness with the condition to return to the demon castle within three years, to have a claim to the throne.
But she does not really feel the urge to do so... or will her secret Chuunibyou heart beat faster at the prospect of becoming the next demon lord after all?