In a sleepy countryside church, Chloe plays the part of a prim and naïve novice, studying to become a cleric. But when night falls, she sneaks out in disguise to win big money at cards! Despite her best efforts, word gets around, and one day a handsome young holy knight named Erald--known as a rising star in the capital--arrives to enlist her help. A murder two years ago threatens the stability of the kingdom, and Erald thinks this card shark in sister's clothes can solve it using her charism--the rare blessing that allows someone to use magic. Little does Heraldo know, there's nothing supernatural about Chloe's winning streak. She's just got a quick wit, and sharp eyes! Will that be enough to survive the den of devils that is the great church?