Lumina, a sister apprentice, was living a peaceful life at church school, but one day her best friend Lina was kidnapped by a mysterious group.
In order to get her best friend back, she uses a skill book left behind by her grandmother, but what was written on it was a naughty skill called "Slutty Magic."
A suspicious new religion has become popular, and incidents occur one after another. What fate awaits Lumina as she continues to use her lewd magic?