B: The Beginning

Crime and action abound in the technologically superior archipelagic nation of Cremona, which was modeled after the actual Italian city of Cremona and other Lombard cities like Milan. One of the main characters is "Murderer B," a vigilante serial killer who has destabilized the city. On the way to achieving their goals, the stories of the protagonist Koku, Keith, a legendary RIS investigator, and an unidentified criminal group are intertwined. Koku is a demihuman who has the capacity to transform some body parts into wings and blades. Keith Flick is seeking to solve the murder of his sister eight years ago while also trying to save his childhood friend Yuna. Both of them are battling the Market Maker, a secretive group that runs the island's government, to learn more about Koku's magical abilities and their origins.