Traditional Japanese bodysuit tattoos are startling to behold, enveloping the shoulders to the buttocks with designs that draw from nature, religion and folklore.

It's rare to see them in the flesh, however, because of their associations with yakuza, organized-crime syndicates whose activities span drug trafficking to the sex industry. In Japan, tattoos are banned in gyms, golf courses, hot springs and spas. Last year, Osaka Mayor Toru Hashimoto launched a crackdown on tattooed government employees, asking them to confess to...