Lately, the city's nights have been stirred by the mysterious phantom thief known as "Rose Noir." He politely sends a calling card before every crime, and each one is invariably accompanied by a single crimson rose. Because he only steals art collected through corruption or treasures seized by the powerful to return them to their rightful places or owners, some have begun to whisper, "Maybe he's actually a good guy...?"

One night, a calling card arrived at the estate of a Duke, one of the most powerful men in the country, along with a single rose.

"Tonight, when the moon climbs to its zenith, I shall partake of the glow of the crimson rose."

The Duke, who owns a massive ruby called the "Queen of Red Roses," raised an outcry, certain that the gem was the target. The jewel was a secret treasure passed down through the royal family of a kingdom that perished centuries ago, and it served as a vital symbol of the Duke's authority. The Duke has established a strict security perimeter, even mobilizing the Royal Knights to prevent the theft. Will they be able to capture him tonight?