The relentless friction of the modern daily grind drives many to dream of escape, to fantasize about a life untethered, but Masafumi Nagasaki actually did it.

In 1992, walking away from a conventional life as a camera technician and a brief stint in Tokyo's entertainment industry, Nagasaki packed a few essentials and stepped off a boat onto Sotobanari—a tiny, kidney-shaped island in Japan’s subtropical Okinawa Prefecture.

On this rugged, uninhabited outpost, Nagasaki stripped away the artificial baggage of civilization, eventually choosing to live entirely clothes-free. He became known globally as the "naked hermit." His existence was a masterclass in minimalist survival.…