Surely it's time the international art world toasted the magnificent cultural conceits of Keiichi Ikemizu, who built a pyramid of logs on top of a mountain to capture a 'thunder demon', then waited a decade for lightning to strike. Ikemizu once walked from Kyoto to Osaka with a dozen sheep in a bid to challenge the boundaries between performer and spectator. While celebrating great eccentrics and visionaries, the critics may also recognise the Zen-like fortitude of Yoshio Yoshimura, who has been holed up in a small mountain village for years, painstakingly drawing photographic reproductions of newspapers with thin pencils. 'This would not be possible without deep and well-balanced breathing,' an introduction to Yoshimura's work helpfully explains. Japan has produced its fair share of po-faced and unimaginative modern art, but you will not find much of it at the Roppongi Crossing exhibition, which opened at the Mori Art Museum last week. The second in a series of one-stop guides to the best of contemporary Japanese visual culture (the first was in 2004), you'll struggle to find a richer, warmer or wackier celebration of creative talent, despite the absence of some of Japan's best-known names. The 36 artists/groups include the 70-year-old Ikemizu, who has been grappling with weighty political and artistic themes since the 1960s, to fresher faces such as Iichiro Tanaka, who just wants to make you laugh with his wry re-appropriations of everyday props. 'We felt it would be too easy to resort to the hackneyed approach of discovering newness by picking only young artists,' says curator Natsumi Araki. 'We were also keen to revisit the revolutionary and innovative work of late career artists.' The guiding principle of the show, says its introduction, was to select work with 'an energy and influence that spreads beyond the confines of conventional artistic categories'. Araki says Roppongi Crossing, which is also the name of a Tokyo landmark close to the Mori, is an opportunity to observe the Japanese art scene as it unfolds. 'The first exhibition was a sort of festival or celebration. This time we've tried to condense the work down, and show where Japanese art might be going.' Hence the subtitle: Future Beats in Japanese Contemporary Art. Yet a small telephone directory could be filled with the big names that are not here. No Yayoi Kusama or Takashi Murakami. No Jun Takahashi or Yoko Ono. The curatorial team often couldn't agree on whom to invite, Araki says. The result is a sprawling, idiosyncratic exhibition that will probably provoke as much head-scratching as viewing pleasure. Painting, sculpture and photography are represented along with design, doll-making and theatre, in the shape of performance group Chelfitsch. When you have bathhouse mural painting sharing the same floor space as interactive mobile-phone software, video game creator Gabin Ito and manga artist Yuichi Yokoyama, you know you're in for a wild cultural ride. Throughout those complicated planning discussions, the curatorial team kept coming back to the show's 'crossing' tag, says Araki, seeking out artists whose work eroded boundaries and easy genre categorisation, and exploring cross-fertilisations between the past and the present. Sixties innovators such as Ikemizu and the late Tiger Tateishi were chosen for their contemporary resonance. Yayoi Deki, a 30-year-old Osaka native whose detailed, hallucinatory paintings have made her a rising star, brings the collection back to the 21st century. The opportunity to see three generations of work shows how up-and-coming creative talent such as Deki have built on the foundations of their artistic peers. Exhibitions that juxtaposition age, talent and genres are hardly new, of course, but Crossings also shreds the boundary between commercial and amateur art. Think of Ikemizu, toiling away at the cultural coalface for decades with little in the way of financial riches, sharing the same floor of the Mori building with software kings and some of Japan's more successful artistic entrepreneurs, such as Masahiko Sato. For Crossings, however, Sato indulged his creative muse, teaming up with academic engineer Takashi Kiriyama to build the Arithmetic Garden, a piece that integrates engineering with art. Dubbed a 'unique combination of order and fantasy, reminiscent of Alice's Adventures in Wonderland', the exhibit is a sort of electronic maze which keeps visitors trapped until they have calculated the number 73. 'It resists categorisation and sums up what this exhibition is about,' Araki says. 'The quality of Japanese art is extremely high, despite the fact that it doesn't get much attention abroad, and virtually no support from the government,' she says. 'Countries such as Britain and Finland do much more to promote their culture and art. We hope this collection [will tell] the world that Japanese art is strong and gritty, that it pushes boundaries and is intelligent.' What will Ikemizu make of it all? It's hard to imagine him enjoying Future Beats in Music, an attempt by the Mori to get to grips with the Tokyo club music and video scene by transplanting to a local nightclub. He would surely approve, however, of The People's Prize, an invitation to vote for the exhibit that makes the strongest impression. The 60s dream of grass-roots democracy is still alive, although not perhaps in the way he imagined. Roppongi Crossing: Future Beats in Japanese Contemporary Art, Mori Art Museum, Roppongi Hills Mori Tower, Tokyo. Ends Jan 14