Kuon Higuro led the semi-criminal gang Sons of the Styx, known as Sanzu's Gaki, wielding influence along the Yamanote line. Detective Kōzaburō Arase dismantled the gang during a police sting, but Higuro escaped by abandoning his comrades. This betrayal cemented his reputation for self-preservation and forged his belief that powerful connections are essential for survival. He frequently declared that "connections are love," showing no mercy to those lacking influential backing. After the gang's collapse, Higuro rebuilt his life as a broker in Shibuya, actively forging alliances with powerful factions. He affiliated with the Agakura clan and later served under Civil A. Sabaramond within the Bastard Children of Sabaramond. He also established a secret alliance with Metropolitan Police Department Chief Superintendent Hideaki Habaki, operating under Sabaramond's protection. His schemes included orchestrating the murder of bartender Nishida to frame associates of the Shinjuku mediator Clarissa. For this, he enlisted Momoya Agakura, utilizing a hidden passage linked to deceased officer Miyabi Hosorogi's past incident to plant Nishida's corpse. Higuro operated with calm ruthlessness, employing lethal force against perceived threats. During the Nishida operation, he killed three thugs, later stating they lacked the connections to challenge him. When former informant Takumi Kuruya interfered, Higuro captured and tortured him. After a confrontation with the resurrected assassin Misaki Sakimiya, he abandoned Momoya during combat and fled. His actions drew police scrutiny when an intercepted phone call to Habaki exposed their collusion. On the call, Higuro reported encountering supernatural phenomena, including Misaki's revival after being killed. Facing exposure and danger, Higuro allied with criminal Hifuki Mushi. He underwent plastic surgery to alter his appearance and fled Japan for the Lugnisas Republic. This escape severed his ties to the Agakura clan and Sabaramond factions, ending his role in Tokyo's underworld. His philosophy of valuing connections above all defined his choices, from betraying his gang to sacrificing allies for survival.