A new law's been passed in Tokyo. Ordinary folks are now allowed to freely carry firearms; shoot, they're even legally allowed to use'em. You might think that crime would increase, and you'd be right. But the arrest rate's gone down. After all, the only prison a dead man needs is a hole in the ground. All thanks to RAPT. The Recent Armed Police of Tokyo is stealing away jurisdiction from the local authorities quicker than a bullet leaves a barrel. What that means is that folks are getting desperate. And desperate people with itchy fingers mean more bodies in the streets. Now, I'm not sure if she came from up above or somewhere way down below, but an angel's just come to Earth. She's an enigma, but with her partners Sei, Amy, and Meg, she's the best chance this town's got. Her name's Jo. And there's a new sheriff in town.