Here are some black and white shots. Many of these, I believe, were taken by Tamotsu Yato in the later half of the 1960s, though some are undoubtedly from more modern sources.
Born in 1928, Tamotsu Yato was a Japanese photographer responsible for pioneering Japanese male photography and creating iconic black-and-white images of the Japanese male. His nude and semi nude models were mostly amateur, unsophisticated countryside men. Yato photographed his male nudes in the 1960's and his work influenced many photographers of the male form worldwide, both in his day and after. He was a friend and collaborator of the famous writer Yukio Mishima whom he also photographed nude. Yato completed three (now rare) high quality photogravure volumes of photography including "Young Samurai: Bodybuilders of Japan" (1967), "Naked Festival: a photo essay" (1969), and "Otoko: Photo-studies of the Young Japanese Male" (1972), before his death in 1973. The last two volumes display dozens of models and countrymen clad only in fundoshi, with "Naked Festival" concentrating on Japan's famous centuries-old Hadaka Matsuri festivals where fundoshi is all that is worn by hundreds of participants.