Together with Hokusai and Hiroshige, Utagawa Kuniyoshi (1797-1861) was one of the great masters of the “floating world”, or Ukiyo-e, school of Japanese art. He lived and worked all his life in Edo, now Tokyo, which was at the time the largest city in the world, with a population of a million. His art was vivid and vital, less graceful than that of his rivals, but possessed by a writhing, paroxysmal energy and exuberance. He specialised in sexy sinuous women, tattooed heroes and colourfully weird demons. His shape-shifting, metamorphic monsters are in a class of their own. He dreamed of horned ghosts and giant skeletons with staring eyes. He dredged up huge sea creatures from hidden depths of fantasy.

Kuniyoshi produced affordable art for the man in the street. His prints were aimed squarely at “the townspeople”, as they were known – meaning artisans and merchants, in the old Confucian hierarchy of Japanese society. But Kuniyoshi’s works were also regarded as a guilty pleasure by the upper classes. Those at the very top of the tree of Edo’s vibrant society, the samurai, bought them by the dozen. His raucous, spectacular, populist art is the direct ancestor of modern Japan’s most vital tradition of popular cartooning, Manga. Such was his widespread appeal that one of his most popular series of woodblock prints, “Biographies of Loyal and Righteous Samurai”, released in 1847, sold a staggering 408,000 sheets. A case can be made for Kuniyoshi as the single best-selling popular artist of the entire nineteenth century, East or West.

Despite his fame, and despite the compelling brilliance and surrealistic strangeness of his work, there has been no major exhibition of Kuniyoshi’s woodblock prints in Britain for nearly 50 years. Now that situation has been put to rights by the Royal Academy, where a wonderfully  diverse show of his work opened, in the Sackler Galleries, last week. Every one of the roughly 150 works on display is a prime, early impression of Kuniyoshi’s work – which was produced, by his publishers, to the most rigorously exacting standards of colour woodblock printing in the entire history of graphic art. The vivid colours, the subtlety of line, and the depth in the tones and half-tones, have to be seen to be believed.

One of the most intriguing aspects of Kuniyoshi’s creative personality was his openness to ideas from the West. Unlike many Japanese artists of his time, he was interested in modern and foreign ideas. A number of his portraits, especially of men, suggest that he might have looked at Northern Renaissance art – or even at recent Japanese experiments in the new medium of photography – while some of his comic prints suggest a brush with Mannerism. He Looks Fierce But He’s a Really Great Guy shows a grotesque human face formed from an assemblage of naked male bodies, which is uncannily close to the works of the sixteenth-century Italian artist Giuseppe Arcimboldo. There is no actual proof that Kuniyoshi knew Arcimboldo’s work, but according to one of his contemporaries, when conversation turned to “Western pictures” the artist reached into a box containing several hundred images from all kinds of occidental sources, including “illustrated newspapers”.

There are plenty of indications of influence running the other way as well. Western artists such as Gauguin and Van Gogh, who had their own well-stocked boxes of Japanese prints, certainly looked at his work’s bold colours and strong, simplified contours. One of the most technically and aesthetically original of Kuniyoshi’s works – star attraction of the section devoted to “Beautiful Women” – is the print entitled Three Women with Umbrellas in a Summer Shower. Three women who have chosen to go barefoot, in the sticky August heat, have been caught in a sudden downpour. They cower under their yellow bamboo umbrellas, giggling at the ferocity of the storm. But here, unusually for Kuniyoshi, the principal fascination lies not in the figures but in the weather – the lines of rain that pour down the picture in a true tour-de-force demonstration both of the designer’s art and his printers’ ingenuity. The heavy shower is rendered in strong, stark lines of grey and black and white, whereas many of the splashes have been rendered in white reserve. An image such as this was surely the source for the bold, slashing lines of rain that tear through some of Van Gogh’s most strikingly expressionistic late Provencal landscapes.

Kuniyoshi seems to have been a proud, truculent, difficult man, with a strong sense of independence. He clashed frequently with the celebrated print-maker who taught him his trade, Toyokuni I, and later became embroiled in a running battle with the censors of the Tokugawa Shogunate. Throughout the 1840s, the authorities tried to crack down on the proliferating prints of the Ukiyo-e school, which they blamed for a general corruption of the Japanese soul. At the height of the so-called “Tenpo reforms”, Kuniyoshi, Hiroshige and other Ukiyo-e artists were called to the office of the magistrate in charge of censorship and forced to sign a declaration renouncing all prints of erotic subjects, Kabuki actors, female geisha, courtesans and dancing women. Kuniyoshi hit back by inventing his so-called “riddle-pictures” – hanji-mono or hanji-e. These were fantastical satires of the government, so oblique and open to varying interpretation that their true meaning was impossible to determine – making Kuniyoshi impossible to prosecute. As an another form of commentary on the absurdity of the new laws, he took to designing pictures of precisely the subjects that had been proscribed, such as the world of courtesan and brothel, but inhabited entirely by animals in human clothing. The pricelessly bizarre Sparrows Impersonating a Brothel Scene is a classic example of Kuniyoshi giving authority the bird.

In one sense, however, Kuniyoshi was served well by the censors. The new rules forced him to focus on Japanese warriors and the tales of the samurai. Such subjects were positively encouraged by the shogunate. They were felt to strengthen the military backbone of a country that was in danger of going soft – a perception sharpened by Britain’s defeat of China in the Opium War of 1839-42, widely seen in Japan as a warning about the shape of things to come.

As the section devoted to “Warriors” demonstrates, these themes brought out the very best in Kuniyoshi. He perfected a new medium, the tryptych-format woodblock print, and his art acquired a new amplitude and monumentality. He illustrated the military exploits of the heroes of old, revelling in tales of magic and the supernatural. Muscular samurai wrestle with giant red carp or octopuses taller than buildings. Bug-eyed warriors scowl and grimace, swords flashing through the colour-saturated air. Blood flows freely. In The Last Stand of the Kusunoki Heroes at Shijo-Nawate – Japanese equivalent to the Greek battle of Thermopylae – arrows cluster as closely as the pours of rain in a summer storm. The dying warriors are pincushioned, their clothes and their flesh seeping crimson stains at once sinister and as beautiful as cherry blossom. The spectacle is fascinatingly gruesome and hauntingly odd, if not especially edifying. “It’s a very uncomfortable imagination,” one lady visitor was heard to remark on the day the exhibition opened. True enough, but what an imagination it was.

The show runs until the beginning of June, before travelling to New York. But that is not the end of the story. All the prints on display have been drawn from the collection of a single individual, the distinguished lawyer and legal scholar Arthur R. Miller. After more than thirty years of collecting Kuniyoshi’s work, he has decided to make a gift of his entire collection to the American Friends of the British Museum. Nearly 2,000 colour prints by Kuniyoshi will enter the collection of the institution’s Department of Prints and Drawings. So the Royal Academy’s exhibition is a celebration, not only of Kuniyoshi’s art, but of the fact that the people of this country will have many more opportunities to appreciate it in the future. The Miller bequest is yet more evidence that when it comes to philanthropy, no one does it better than rich and cultivated Americans. Disgraced British bankers retiring with large amounts of controversially acquired cash might care to take note.