Aya, Yoji, Ken, and Omi form the quartet that makes up Weiss Kreuz (WK), an assassin unit that eliminates threats to society. Each member specializes in a distinct fighting style: Aya wields a katana, Yoji masters strangulation with strings, Ken fights with lethal metal claws, and Omi employs a wide array of projectiles. Under the orders of a mysterious figure known only as Persia, WK is sent to eliminate drug rings, terrorist groups, and similar threats. As they carry out their missions, they discover that many, perhaps all, of the adversaries they confront are connected to the powerful Takatori family. The Takatori family is wealthy, influential, and powerful. It seems …