Staying at the top of the game after 10 years is no mean feat in Japan's fickle music business. As one of the first artists to bring American-style R&B to these shores, Double's achievements are doubly impressive. And now she's celebrating her first decade with an album of collaborations with Japanese and American artists such as De La Soul, Ak'sent, AI and Kreva. To top it off comes "Black Diamond," a pulsating duet with self-styled "Queen of hip-pop" Namie Amuro.

Back in 1998, Takako Hirasawa and her sister Sachiko were a revolutionary duo. The mid-'90s had seen dance-pop music dominate the Japanese charts, with R&B no more than a niche genre. When their older sister brought back CDs from the States, the Niigata duo got hooked on artists such as Janet Jackson and TLC, and were soon playing at the Yokota U.S. Air Force base.

The initial success of their singles led to their debut album "Crystal" charting at No. 2 in June 1999, but tragedy had struck just a week prior when Sachiko died suddenly of a blood disease. Takako withdrew from music for a year, but was to come back even stronger.