Fans of irezumi (one of many Japanese words for tattoos) might want to wander over to this website and order a copy of a volume of Japanese Tattoo Ladies, a publication which covers the topic of its title. You can order back copies of this publication, as well as other works on Japanese tattoos. It would help you a lot if you can read Japanese. Otherwise you're restricted to looking at the tiny pictures and dreaming.
Utamaro no Shunga by Paul Binnie, born 1967 copyright Paul Binnie
The illustration above comes from one of the most scholarly and deep websites on the net about all aspects of Asian art, including Japanese tattoo art. The site is worth a visit. And while you're there you can buy items or bid on them at their auctions.
Today's Japanese tattoo vocabulary includes horimono, irezumi and oukoshisei. All three words mean tattoo. Horimono can mean ancient penal tattoos as well as modern or ancient artistic tattoos. Irezumi and oukoshisei usually mean penal tattoos.
The illustration above is a print, not a tattoo, although it obviously includes a tattoo in its subject. The word shunga is used in Japanese to refer to erotic artworks. Many of the classical shunga in Japanese art depict quite exaggerated genitals, which I guess were considered aesthetically appealing.