It's derived from the day's date in Japanese -- SAn, maRU, SAn, get it? -- but it's really just a good excuse for a party. And a party it will be. This year, the third annual event will showcase West Coast salsa phenomenon Johnny Polanco y Su Conjunto Amistad and feature the vocals of Ray De La Paz, one of the most renowned singers in modern salsa.

Polanco has been tearing up Latin clubs in Los Angeles for years. He's also garnered Latin Grammy nominations and appeared as a guest on major Latin CDs. Polanco is a master of the tres, a six-stringed instrument that creates the signature sound of son, the Cuban style of music that was the precursor of modern-day salsa.

In salsa bands, the harmonic tension of this taut, tangy "guitar" forms a central harmony floating over the intricate rhythms of the percussion section. Polanco draws his rhythms from Puerto Rican salsa, with plenty of Dominican and Cuban influences in the mix.

However, not satisfied with being one of the most in-demand tres players, on his own recordings the multi-instrumentalist Polanco plays trombone, conga and vibes. He helps prime every section of the band for tightly composed and explosive performances. Last year's "Pa'l Bailador" catches the band's scorching dance rhythms and the yearning honesty of its ballads. Featured on the CD is De La Paz, whose wry phrasing and out-front sexiness is guaranteed to whip the crowd into a dancing frenzy. This will most definitely not be a sit-down affair.

Both evenings kick off with a salsa competition, giving dancers a chance to show off what they've learned at Tokyo's innumerable Latin dance schools. If you've never danced salsa, don't worry -- a short lesson will be offered before Polanco and his band take the stage. It's maybe best to stretch out before you go. It's guaranteed to be a looong night.