A pulsating mambo fills the air at a cavernous club near Tokyo Bay. "Ayyy-esssooo!" the song calls in exhortation as a sea of dancers -- sweaty, skin bared, clothes clinging -- roll their hips and hurtle into turns with increasing abandon.

The scene is a world away from the formal and orderly Japan that lies beyond these walls -- and that's exactly why these dancers love it.

Salsa, the catchall name for a variety of music and dance with Latin and Afro-Caribbean roots such as the mambo, rumba and Cuban son, has found an unlikely group of hard-core enthusiasts in Japan.