Hōzen Ōyama, designated Perman No. 4 and commonly known as Peryan, serves as the oldest member of the Perman superhero team. He consistently displays a pragmatic and strategic mindset, functioning as the group's primary tactician during missions. His advanced age—typically 14 years old, though one source cites 18—fosters a mature outlook and responsible demeanor.

Operating independently from the core team, Hōzen resides in Osaka. Earlier depictions note his background as a Buddhist monk, while later adaptations emphasize his diverse part-time jobs and entrepreneurial ambition to found a large company for financial success. This pragmatic nature extends to his superhero role, where he deploys unconventional or intelligent solutions to crises, utilizing mental toughness and a strong sense of responsibility.

His interactions position him as a mediator, especially in conflicts between Perman No. 1 (Mitsuo Suwa) and Perman No. 3 (Sumire Hoshino/Perko). While he occasionally exhibits greed or self-interest towards fellow Permans, he ultimately proves reliable in supporting them during challenges.

Regarding "Pa-Pa-Pa The★Movie: Perman - Tako de Pon! Ashi ha Pon!", available records do not indicate Peryan's participation or role. The film's synopsis centers on the kidnapping of Sumire Hoshino (Perman No. 3) by Dr. Octo and Mitsuo Suwa's (Perman No. 1) rescue mission, with Peryan absent from plot summaries and character lists. His established role as a strategist suggests no direct contribution to this specific event.

Across the broader franchise, including manga and television series, Hōzen Ōyama remains defined by intelligence, resourcefulness, and occasional pragmatism bordering on opportunism. His development highlights complex problem-solving capability and unwavering dedication to the team's objectives, even while operating from a geographical distance.