HARRY MOUNT: Is this the naughtiest art show Britain's ever seen? And the most shocking thing of all is that it's at the British Museum! By Harry Mount Thought Japan was all refined manners, cherry blossom and sensitive pictures of Mount Fuji? You may need to think again. A new exhibition at the British Museum will blow the lid off the modern image of the Japanese as shy, demure people - and reveals what an extremely sexually liberated nation they once were. From 1600 to 1900 - before Westerners turned up and filled their heads with prudish thoughts - they produced some of the most sexually graphic, yet openly published, art the world has seen. A new exhibition at the British Museum will blow the lid off the modern image of the Japanese as shy people - and reveals what a sexually liberated nation they once were. Pictured, a painting by Sugimira Jihei So graphic is the British Museum's show, in fact, that for the first time curators are to introduce an age limit for visitors. Any children under 16 must be accompanied by an adult, and parents with children under 14 will be warned that the show features sexually explicit images. In Utagawa Toyoharu's work, Courtesans Of The Tamaya House, a group of prostitutes are shown in a brothel awaiting clients. Even Neil MacGregor, the scholarly director of the museum, is pretty straightforward about the nature of the picture. "This is a finishing school for tarts," he says. You can see all the skills that a successful tart has to know. It's certainly an exhibition in which children all have to be accompanied by an adult. Yet this is one of the less graphic pictures from the period. It shows a group of high-ranking prostitutes in the lattice-windowed "display" room of the brothel. As they wait for clients, they brush up on hobbies that might appeal to customers: one plays a shamisen, a three-stringed Japanese musical instrument; another sews. Neil MacGregor, the scholarly director of the museum, says: 'It's certainly an exhibition in which children all have to be accompanied by an adult' Other pictures from the period are much, much more explicit. In The Dream of the Fisherman's Wife, painted by Katsushika Hokusai in 1814, the fisherman's wife in question has an extremely active imagination. We see her ravished in every conceivable way by a father-and-son pair of octopuses. To put it politely, the animals use their 16 arms in an inventive fashion, wrapping them around her pale limbs and torso. And how does she react to this importunity? Well, let's just say she doesn't look like she's missing her fisherman much. The picture was accompanied by red-blooded text with lots of wriggling and ecstatic moaning. It goes on at length - and in some detail. Two centuries after the picture was made, the dialogue between the octopus and the fisherman's wife is too explicit for a family paper. From 1600 to 1900, private individuals were left to their own devices to do pretty much what they wanted sexually - and to illustrate pretty much what they wanted, too At the time, though, this stuff wasn't considered furtive pornography for the early 19th-century Japanese dirty mac brigade. It was utterly mainstream, out-in-the-open art, for men and women alike. The man who produced the octopus picture, Katsushika Hokusai, is probably Japan's best-known artist, famed for his image of a cresting, tumbling wave and picture-postcard pretty views of the country: Mount Fuji wreathed in clouds, cherry blossom, girls in kimonos. The explicit pictures, prints and illustrated books were given the name "shunga," originally a Chinese word meaning "spring pictures." "Spring" was a euphemism for sex - but that was just about the only coy thing about the art of shunga. From 1600 to 1900, private individuals were left to their own devices to do pretty much what they wanted sexually - and to illustrate pretty much what they wanted, too. Early modern Japan wasn't a free-for-all orgy, but the culture was astonishingly free - particularly compared to contemporary Western values - when it came to the open enjoyment of sex. Shunga is unique in pre-modern global culture. The shunga school of art flourished just as Japan's geisha girls were at their peak. These were professional hostesses who entertained men with games, dancing, classical music - and sometimes more While grand British and continental pictures veiled the sexual act with obscure references to nude Classical figures - Venus, Cupid, sundry nymphs and centaurs - nothing was left to the imagination in shunga: it was all out there. In another Hokusai picture, The Adonis Plant, painted in 1823, a couple carefully position themselves so that their outsized genitalia are on full view to the artist. You could call it a sort of sex manual, except that the workmanship is so precise, detailed and beautifully painted that it is also a superlative work of art. These were professional hostesses who entertained men with games, dancing, classical music - and sometimes more. "The geisha girls are there - then as now - to be entertaining and amusing companions," says Harriet Sergeant, an author who lived in Japan for seven years and wrote a memoir of her time there called The Old Sow In The Back Room. From 1600 to 1900 the Japanese produced some of the most sexually graphic, yet openly published, art the world has seen. Pictured, Lovers in the Upstairs Room of a Teahouse, by Kitagawa Utamaro Among Japanese men, this phrase is an unkind nickname for a wife - an unlovely counterpart to the beautiful geisha girl. "Today, there's a strong sexual element to geisha girls," says Sergeant. The wife is stuck at home with the children while the man goes out for clever and amusing chat in the evening with the geishas. They pay for their company and, afterwards, might go to bed with them - but they're not paying merely for sex. It's very different from being a prostitute. In Japanese culture at that time, sexual freedom was encouraged. Shinto - the Japanese set of spiritual beliefs - positively celebrated the joyful union of the sexes. And so graphic depictions of sexual activity, such as the lesbians in the first picture at the top of this article, were never thought spiritually wrong or degenerate. Technological advances in mass printing in the 17th century led to an explosion in shunga buying among the emerging middle classes - including many avid female fans. If you head to the British Museum next month, then prepare yourself for a glimpse inside the Japanese psyche, ancient and modern, in all its beautiful - and sometimes eye-popping - glory When full-colour printing came along in 1765, shunga entered its golden age. The skills of artists like Hokusai were combined with the best technology, and the most liberal code of sexual mores, to produce the beauties, and excesses, of the fisherman's wife and her extremely fertile imagination. That sexual freedom lasted until 1868, when Edo (modern Tokyo) was lost by the ruling administration to the Emperor Meiji, whose descendant, Emperor Akihito, still rules Japan today. With the return of imperial rule, Japan opened up to the West for the first time in three centuries. The influence of late Victorian Western values had a powerful effect on the freewheeling sexual mores of shunga. "All sorts of things changed," says Harriet Sergeant. The Japanese used to swim naked in hot springs, in mixed sexes. Then the government insisted they bathe separately. Shunga entered a long twilight period, almost forgotten, until its rediscovery in the modern era. Relaxation of strict censorship in the 1947 Japanese constitution has been allied with a more liberal social attitude in recent decades. This has led to a revival of interest in shunga as a national art form, not far removed from that other national art form, manga - comics - that can be highly sexually graphic, too. Today, that centuries-old liberal attitude to sex lingers beneath the polite Japanese exterior. "Tokyo is still chock-a-block with the most sexually liberated nightlife," says Sergeant. They have a much more relaxed attitude towards sex than we do. We talk about sex but don't do it very much; the Japanese are very discreet about it, but do it much more. If you head to the British Museum next month, then prepare yourself for a glimpse inside the Japanese psyche, ancient and modern, in all its beautiful - and sometimes eye-popping - glory. Shunga: Sex And Humour In Japanese Art, 1600-1900 opens at the British Museum in October.