Kentarō Ushiro works at a paranormal research institute, professionally engaged with supernatural phenomena. He is the father of Ichitarō Ushiro, the psychic protagonist. Kentarō's work involves direct investigation of paranormal occurrences, including a poltergeist incident shown in the OVA's second episode.

During this investigation, Kentarō cites historical paranormal cases and figures. He references the Hydesville, New York incident as purported evidence for poltergeists, though it was a hoax. He also mentions Charles Richet, identified as the discoverer of ectoplasm, despite Richet's primary Nobel Prize recognition being for work on anaphylaxis.

Kentarō's expertise positions him as a guide during spiritual crises. When the poltergeist possesses Ichitarō and the guardian spirit Hyakutarō fails to intervene, another psychic named Funakoshi performs the exorcism. This event leads Ichitarō to seek closer ties with his guardian spirit, prompting Kentarō to support his son's subsequent spiritual journey.