"Are you enjoying being the black rider that's been spotted all over Ikebukuro for a few years now? Why is it that you're riding such a dangerous bike all over the place? Are you aware that you're violating the law?!" Ikebukuro, Tokyo. A place full of fires waiting to be lit, and plenty of people ready to light a match - twins who are the perfect opposite of each other. An idol who's nothing like her older brother. A girl with a crush on her senior in the Dollars. And a headless rider with a bounty on her... uh, head. Keeping the peace is probably not gonna happen.