Ryoko Monma acts as a central antagonist, orchestrating a series of police officer suicides. She employs supernatural abilities to compel her victims into taking their own lives. This power directly targets the protagonist, Goku, during their confrontation; to resist her control and survive, he is forced to blind himself by stabbing out one of his eyes. Her actions form part of a larger conspiracy involving powerful figures known as underground rulers. After Goku acquires a cybernetic eye implant and an extendable rod weapon, he resumes his investigation and uncovers her deeper connections to this clandestine network.