Mario Higuma operates directly under the King's authority within the tower structure. His position involves interacting with challengers, including the Card Professor. Higuma possesses black hair, black eyes, a bindi, and piercings. Character tags indicate he is manipulative.

During the critical story arc "Cracked World," Higuma replaces his body to assume the form of Bio-Token No. 9. In this form, he appears before Hiyori Munenashi and others. Higuma confronts Eclair, later revealed to be Reira Kanagi. Reira challenges him to a battle, referencing a prior encounter between them. This conflict serves as a narrative device to reveal details about Reira's background, specifically her past employment as a guard and her motivations for opposing Higuma.