Thirteen-year-old Akinori Arihoshi is a fair-skinned, heavyset boy with brown spiky hair, thick eyebrows, and brown eyes, typically wearing traditional Japanese attire including a white kosode, dark purple hakama, zori sandals, and a necklace of green Buddhist prayer beads. He descends from the Arihoshi family, a centuries-old lineage of magical practitioners specializing in yo-kai energy manipulation and divination. Trained by his grandmother Mitsue, he masters ancestral arts of yo-kai perception and spiritual rites, able to command yo-kai without mechanical devices. A founding member and self-appointed leader of the Yo-kai Detective Agency based in his ancestral home in Springdale, he collaborates with Natsume Amano and Touma Tsukinami, displaying a confident demeanor that masks deep insecurities about his physique. He wields protective magic, tracing stars in midair to create offensive or defensive constructs, and later receives the Yo-kai Watch Animus from the celestial yo-kai Suzaku, enabling him to summon powerful Celestial yo-kai using triangular ark discs. Using a spectral radar gifted by his grandmother, he detects supernatural threats such as the Onimaro virus outbreak. He confronts adversaries including the Oni King Rasen, and a pivotal revelation identifies him as the reincarnation of Hakushu, also known as Eurus, one of the ancient knights who served the yo-kai Juno.