Imagine meeting Superman and discovering that, off-screen, he is a leading member of a classical theatre dynasty – the Redgraves, perhaps. Nomura Mansai, casually glamorous, looking younger than his 35 years and about to appear on London's Globe stage, just about fits the Japanese equivalent of such a description. A drawing based on him has a starring role as On-myo-ji, a Japanese shaman of the early middle ages, in a popular manga novel soon to be turned into a big-budget film. But he is also the scion of a Kyogen family, the Mansaku clan, which has passed down its arcane skills for at least 200 years, through eight generations. There are only 120 professional Kyogen actors in Japan, 13 of them in the Mansaku company, of whom three belong to the Nomura family.
But what is Kyogen? Other Japanese theatre forms are better known here. Kabuki, with its combination of ritual and earthiness is relatively familiar. Noh, stately, choreographed and funereally slow, is respected, if rarely seen here. Kyogen, which is made up of two Chinese characters meaning "words" and "crazy", comes from the same roots as Noh. Both have their origins in the acrobatics, mimicry and circus skills of Sangaku, an entertainment which came to Japan from China 1,000 years ago. Gradually two forms developed, both exclusive to men, with the short, humorous plays of Kyogen providing light relief for the solemn Noh dramas. These were not subversive, but existed, as Mansai puts it, "within the system, like a court jester". These days, Kyogen has a following in its own right and Mansai, a popular actor in Japanese cinema and on television, is attracting younger audiences to it.
Mansai went through a teenage rebellious period, dreaming of being a baseball player, a chef or even a diplomat. But he is happy enough with his role now: "I have come to appreciate the techniques and skills needed and the way they can be used to express something." He is a passionate defender of the old ways, outraged that Kabuki "gets three pages in the dictionary and Kyogen one line", but he knows that change means that "classical theatre is still living, breathing". Hence the newly-written, Kyogen-style plays such as The Kyogen of Errors, based on Shakespeare's Comedy of Errors, which he and his father are bringing to London as part of Japan 2001.
At the Noh theatre in Tokyo, Mansai, whose grandfather was designated "a living national treasure", talked about his training. His first role was, aged three, as a monkey in a popular playlet called The Monkeyskin Quiver. As he grew up and took leading roles, Mansai says that he "tried to reproduce exactly the impression my father made, despite being physically different". Movements in Kyogen are stylised and often have significance in characterisation. The actors develop disciplined vocal techniques combining deep-chest and high, swooping sounds, quite unlike what Mansai describes as the "melodious modulation" of the west.
In London in May to look at the Globe stage, for which Kyogen of Errors has been specially devised, Mansai was just a little apprehensive. The traditional long walkway, along which Noh and Kyogen actors usually enter, will not be available. Masks are not much of a feature of Kyogen, being used mainly for animals or grotesque caricatures, but they will have a particular role at the Globe. Mansai is to play both twin servants in this complicated farce of mistaken identity, and his father will play both masters. Masks will be donned to signify that a servant is talking to the "wrong" master and vice versa. There will be surtitles for those who can't bear to miss a word.
"The technique is simple and the possibility for development endless," Mansai says. "This could be Kyogen's century."
Kyogen of Errors: Shakespeare's Globe, SE1 (020 7401 9919), 18 to 22 July