It consists of nine 19th-century coloured woodblock prints, including some by very famous artists. The Japanese called this manner of art Ukiyo-e, floating world pictures representing the fleeting pleasures of our transitory lives. Some were paintings but most were prints.
Many were portraits of actors and courtesans, landscape really only developed as a subject in the 1830s. But this genre, Shunga, meaning ''spring pictures'' deal directly with sex.
Apart from one, these are graphic in showing organs and sexual acts. If you dislike such things be warned.
Some would classify these as pornography just because of this content. Attempting to distinguish erotic art from pornography is notoriously a fool's errand.
Any plausible definition says erotic art must have aesthetic qualities and includes some condition that it shouldn't offend common standards of decency.
The trouble is, of course, these vary from time to time and place to place and even between different groups in the same time and place. The definitions rarely settle any disputes.
In fact, almost all societies at all times have had forms of erotic art. But when you look at Japanese material it's unlike that of post-Classical Europe or even the orgiastic art produced in India. It is focused on the pleasure and the passion of the sexual act rather than showing sex as a romantic ideal of love or a means of religious worship.
This is because of different religious backgrounds. Post-Classical Europe was Christian and Christianity generally confines sex to marriage and sees its proper role as for reproduction only.
Against this background, erotic art tended to confine itself to classical mythology or representing sex as an expression of romantic love. In India, numerous Hindu sects use erotic symbolism because divine procreation was seen as the source of creation.
Things which seem shocking to Western eyes, such as goddesses having sex with various animals, arise from the belief that this was necessary to produce and renew each species.
The sex depicted is often ritualistic and there were illustrated manuals explaining how to do it properly. Tantricism appears to hold that orgasm is a form of transcendence, of communion with the divine.
The Japanese background is different again. Shinto, the principal religion of old Japan, holds that people were created by sex between a god and goddess.
The act was performed on the August Celestial Pillar, and the core of the creed was phallic worship. Sex was seen as fundamentally good and the pleasures of the flesh, whether gay or heterosexual, as natural and normal.
Shunga, including those in this exhibition, rarely show people entirely naked. They make much use of elaborate, beautifully patterned and draped costume.
They were advertisements for the courtesans who worked in the red light districts and were fashion plates as well as aiming to show the heights of passion to be achieved with the advertisers. The linearity of Japanese art lends itself to the expression of such things.
The genitals exposed are often exaggerated in ways that can seem grotesque. It has been suggested this is because natural shaped phalluses were so common in Shinto Japan exaggeration was required to produce a greater effect.
Though none of those here show violent or non-consensual sex, plenty of Shunga do as they also show extraordinary fantasies.
Hokusai's The Dream of the Fisherman's Wife c.1820 shows an entirely nude woman swooning on rocks while a large octopus performs acts on her and a little one kisses and fondles her.
In the violent scenes of non-consensual sex the males are sometimes spirits, hairy monsters or just ruffians who are very hairy and malign.
To Japanese people Europeans are hirsute which could be seen as proof of our savagery and viewed with mingled horror and excitement.
Europeans sometimes figure in Shunga for the drama and intensification of feeling this could produce. They are a form of expressionism focused on sex and aiming to render the extremes of passion.
From time to time there were efforts to reign them in. In 1722, the Confucian Tokugawa government issued edicts curbing them. This gave rise to Abuna-e, ''dangerous pictures'' which did not show pubic hair or organs.
Although the curbs didn't last long, the new sub-genre survived and number 5 in the exhibition, Keisai Eisen's Secret Language of the Courtesan, issued about 1822-25, is an example.
The couple are clearly not just having a polite conversation but nor are their genitals exposed. Both are beautifully dressed in patterned clothes and the woman's bowed head, opened mouth and curling fingers express her feeling. Her lover holds one hand. Her headdress is very wonderful.
There have been Shunga exhibitions in Dunedin before but this is a very good one.
Peter Entwisle is a Dunedin curator, historian and writer.
