One Japanese comedy expert in Osaka appeared to confirm that view when he told me earlier this month, "the rule is that if it doesn't hurt, it won't be funny". Another, meanwhile, vouchsafed the information that "to succeed in Japanese comedy, you have to drop your trousers". Enter Clive James' repeated smirking at the quaint ways of those "funny foreigners" and the cliche is complete.
Issey Ogata is out to overturn those myths. A consummate character comedian, he has been described in the past as "a Japanese Mr Bean, Tokyo's Woody Allen and Nippon's Robin Williams". In fact, he's more like an oriental cross between Steve Coogan and Harry Enfield, pointing up the absurdities of society by putting some of its more ridiculous types on stage. In so doing, he singlehandedly dispels another hoary old piece of hand-me-down knowledge - that the "inscrutable" Japanese are a people incapable of laughing at themselves.
The embodiment of that overworked phrase "big in Japan", Ogata's concerts in his homeland sell out in 20 minutes flat. We witnessed people (mainly trendy, black-clad youngsters) queuing up for returns five hours before his performance at the Kinetsu Theatre in Osaka. He has a 56,000-strong fan club, and his 25 videos sell like hot rice-cakes. This week, as he opens a three-week run at the Lyric Theatre, Shaftesbury Avenue, aided by simultaneous translation through headphones, we will get a chance to see what all the fuss is about.
Duncan Hamilton, an Irish actor who has lived in Japan for 10 years, has a Japanese wife and is Ogata's sometime interpreter, admits that "everyone has the idea that the Japanese have this crazy sense of humour, but that's not fair. It may be difficult to believe when you watch the excesses of Japanese TV or the Tokyo Shock Boys lighting their own farts, but when you live here you realise Japanese humour is actually very subtle."
Ogata backs that up. He's fighting against that most diffcult foe: received wisdom. Sitting inconspicuously in the foyer while smoking nervously before his performance, the 45-year-old performer asserts that: "A lot of people think the Japanese don't joke very much. Traditionally in Japanese society, you have to march in time with the person beside you, and ask for permission before laughing. I'm doing battle with that mentality. I think people here want to be able to laugh. I want to blow away that expressionless image."
His style is certainly viewed as revolutionary in Japan, because his characters are based in a reality far removed from the highly stylised mask or white-face manifestations of traditional Japanese theatre: noh, kabuki, manzai, rakugo and kyogen. "Most Japanese drama schools teach a strict acting style which has no connection to daily life," Ogata says. "I felt acting should deal with what people are really like. I didn't like the way actors here performed theatre as though it were something strange."
As a result, this former building-site worker and his long-time director, Yuzo Morita, have worked up more than 200 distinctive, "slice-of-life" sketches over the last 25 years. Even so, when he first performed in front of some of Japan's leading actors, Ogata recalls, "one of them got so angry he got up and shouted 'this isn't entertainment. Mind your Ps and Qs.' It was too close to the bone for him."
It's all very well shaking things up over there, but how will he go down over here? Won't his show lose a lot in translation? Will he prove as popular a Japanese export as, say, personal stereos? On the evidence of his show in Osaka, he has every chance of succeeding. Watching him metamorphose before our very eyes into different characters for seven 15-minute vignettes, it was a case of "never mind the language, feel the performance". You might not understand his every word and you may smile rather than belly- laugh, but Ogata's magnetic stage-presence is unmistakable.
As is his universality. Ogata portrays figures who are identifiable in any culture - the stressed-out "salaryman", the middle-aged mummy's boy, the incomprehensible, foaming-at-the-mouth politician, the dodgy pyramid- salesman, the dissatisfied barmaid, the inadequate terrified of foreigners. (Morita reckons that Ogata's range also confounds stereotypes: "In the West there's this image that all Asians look alike and have the same expression. English audiences may be suprised by Issey's versatility.")
In one memorable skit, a middle-aged wage-slave tries to convince his (invisible) rebellious son to follow in his footsteps by slapping him on the back in the most clumsy and inappropriate manner. The lack of understanding between the generations is a theme applicable in any country. As Ogata's tour manager, Elmar Weinmyr, a German based in Japan, whispers to me during the performance: "You could have exactly the same conversation between a suburban commuter and his son in London. These sketches aren't just about Japan." Morita chimes in: "The gap between self-image and reality is a universal phenomenon."
Ogata's currency is the dislocated and the marginalised - particularly relevant in Japan, a country now gripped by a breakdown of its rigid, traditional structure and paralysed by an unaccustomed economic crisis. Morita explains that "Issey tells the stories of the people who would never otherwise have their stories told. They are all hopeless. It's the theatre of the dispossessed."
His fans appear to agree. After Ogata's show in Osaka, a queue of them snaked round the foyer waiting for the man to sign copies of his latest video. As she patiently bided her time - she was obviously in for a long wait - 54-year-old Yamamoto Harume assessed his appeal: "Nowadays, a lot of people have problems in their lives, and he portrays that with great reality. Ogata plays weak people - and every man and woman can recognise and feel compassion for that," she observed, before adding with a laugh: "You should have him on the BBC."
Issey Ogata is at the Lyric Theatre, Shaftesbury Ave, London, W1 (0171- 494 5045) from 24 Feb to 14 Mar.