From the introduction:
A picturesque harbor city ... a brooding nexus of occult forces ... where sea-demons wail on the rocks at midnight and tourists line up to take pictures of the historic lighthouse at noon. It’s the prettiest city in the nation, built in little pockets or townships on the Del Rey Peninsula in coastal California. It also happens to house an enormous, slumbering demon inside its central mountain range. This is Diablo Del Rey, at once the scariest and most fun city in the world.
This mini-supplement does not present a realistic setting. It’s an urban backdrop with a strong dose of dark magic and demon-stuff, and let’s not get hung up on how that relates to national economy or history or anything like that. It’s based on Japanese animé film and some similar sources, and the setting is a reasonably interesting excuse for grotesquerie, crime-solving, a little bit of humor and soap opera, and knock-down, drag-out action.
The Demon Cops, about a dozen individuals total, are part of the Diablo Del Rey police department. Some of them use non-sorcerer police partners and some don’t. The squad came into existence about 30 years ago to combat the vicious, wide- spread sacrifice cults that infested the Peninsula , who exploited the darker aspects of the Del Rey Demon’s sleeping psyche through sacrificing appropriate “triggers.”
Today, the Cops consider themselves overt heirs to the legacy of Kaspar Tweet, the sorcerer who led the fight against the cults; he died about ten years ago. Since the cults are now mainly gone, the Demon Cops’ duties have expanded to cover any and all demonic weirdness insofar as it affects the well-being of the people of the city. And there’s plenty of it, too."