Seijo wo Kubi ni nattara, Naze ka Youjoka shite Maou no Pet ni narimashita.

A former saintess, Presea, was falsely accused and executed.

She thought that her life was over, but somehow she is reincarnated as a young girl in the castle of the Demon Lord, the sworn enemy of humans. She tries to escape from the castle before they find out she is a human saint, but...!