MAKOTO AIDA’S first retrospective is 250 metres above ground in the Mori Art Museum, on top of one of Tokyo’s swankiest skyscrapers. But there is nothing rarefied about the collection itself. Part of its charm is that it appears to have poured out of what the artist calls his “skewed” mind in a cascade of impish disorder.

There are doe-eyed girls in various states of undress, smiling and languishingly carefree. It takes a moment to realise that the one winking mischievously in “Harakiri School Girls” is disembowelling herself with a samurai sword. Or that the frolicking nudes in his latest (unfinished) work—spread over a large wall—are being blown to bits by a gun, their insides spilling out in a puff of flowers, strawberries and diamonds.

It is hard to tell whether “War Picture Returns”—a homage to the disgraced second world war artists who did their jobs of glorifying Japan’s war machine all too well—is pro- or anti-war. Mr Aida insists there is nothing political about works such as “A Picture of an Air Raid on New York City”, which shows Japanese “Zero” fighters in an infinity formation flying over a flaming Manhattan. It came, he says, from a mind overcrowded with images after watching too many war films.

Some work, which gently parodies Japanese masterpieces, reveals what a deft and meticulous painter he is. To some, his video impersonation of a drunken Osama bin Laden claiming to have found peace at last in a Japanese izakaya, or pub, is just plain funny.

But perhaps most intriguing is that the 47-year-old’s exhibition is taking place at all. His contemporary, Takashi Murakami, has recommended that any Japanese contemporary artist who wants to become rich and famous should make it outside Japan first, in order to be accepted at home. Mr Aida has not followed Mr Murakami’s advice. He has only rarely lived abroad; some of his drollest work mocks the difficulty of speaking English (“Stop Speaking with Trilled Rs”, he complains). He makes paintings that he admits are often too erotic for public museums, too grotesque for people’s living rooms and too laced with a Lolita complex for non-Japanese tastes.

He says he never thinks of collectors. One piece, “How to Become the World’s Greatest Artist”, could be a sly dig at Mr Murakami’s celebrated commercialism. The work recommends greeting art-world big shots with “Eh? What’s your name again?” Even better, it says, “go ahead and punch them for no reason whatsoever.”

Yet recognition is starting to creep up on Mr Aida—in Japan at least, if not in the West. He, too, seems to be adapting in middle age to the sensitivities of the market. A room in the exhibition containing his most risqué manga, paintings and video is sealed off, like a peep show, from under 18-year-olds. He admits he is toning down the eroticism in some of his larger works so that they can hang in public museums. He will, however, continue to portray “pretty young girls”, he insists. Not only does he find them the most fun to paint; they also represent what he calls the emasculation of Japan’s male society after its wartime defeat.

But Mr Aida will face an uphill struggle for public approval. One of his admiring critics, Akira Tatehata, president of the Kyoto City University of Art, says the artist is still too “dangerous” for the general public—though his brand of eccentricity should be encouraged. Some in Japan wonder why Mori, a company with annual sales of $2 billion and that builds skyscrapers for the uptown elite, should promote such a downtown hellraiser as Mr Aida or indeed those other iconoclastic Asian artists, China’s Ai Weiwei and South Korea’s Lee Bul. That it does is just another of the incongruities of this exhibition.