Hōzen Ōyama is Perman No. 4, a pragmatic and level-headed 14-year-old Buddhist monk residing in Osaka. As the oldest member of the Perman team operating under the alias Paryan, his mental fortitude and strong sense of responsibility are defining traits. He frequently acts as a strategic counterbalance to his teammates' more impulsive tendencies, developing unconventional or effective plans crucial for resolving the group's complex challenges.

Demonstrating superior intelligence and capability among the five Permans, he often takes the lead in devising mission solutions. He also serves as a mediator, adept at resolving conflicts between Perman No. 1 (Mitsuo Suwa) and Perman No. 3 (Sumire Hoshino/Pako). While occasionally displaying greed or self-interest towards his fellow Permans, he ultimately shows a willingness to support them and assist with their problems.

Beyond his superhero duties, Hōzen harbors a personal ambition to become the owner of a large company and achieve significant financial success, a goal reflecting a contrasting dimension to his life as both a monk and a superhero.