Jii serves as the enigmatic bodyguard of Yao Sakurakouji, his origins, birthdate, and real name concealed from public knowledge. His unwavering loyalty to the Sakurakouji family spans roles beyond protection—butler, mechanic, mercenary, and trainer of professional wrestlers—reflecting a vast, adaptable skillset. Episodic flashbacks humorously unveil a past threaded with incongruous professions: military service, Oscar-winning acting, touring musician, Buddhist monastic life, and covert intelligence work, all portrayed with exaggerated, near-superhuman flair. His resilience is wryly likened to iron, surviving absurd scenarios unscathed. During missions, he maintains a stoic, silent presence, clad in sunglasses, piloting armored vehicles or executing tasks with mechanical precision. Interactions remain task-focused, avoiding personal history or casual dialogue. No supplemental media expands his narrative beyond the primary series, leaving his enigmatic legacy intact.