It's been 10 years since Ami and Yumi shot to fame with the million-selling debut single "Ajia no Junshin," and it's almost unthinkable that a manufactured pop duo should last so long. But Puffy's strength has always been in embracing the unpredictable, and "Splurge" is a confident, mature pop album that will catch any fan off guard.

While their sound has always been touched by the blues-rock sensibilities of mentor Tamio Okuda, this is by far their most raucous set. Guitar Wolf and Jon Spencer blast a boozy rockabilly groove on "Jo Mashin Gan" and Okuda returns for the growling "Mogura Raiku," on which the girls spit staccato vocals. "Shall We Dance" delivers synthed-up new wave that recalls Okuda's old band Unicorn, and "Mogura," written by Blue Hearts and High-Lows legend Hiroto Komoto, is excellently bonkers.

Despite the mish-mash of songwriters, "Splurge" somehow avoids a too-many-cooks meltdown and instead sounds deliciously diverse. Even low points such as "Tokyo I'm On My Way" are forgivable: A horrible song written by Offspring frontman Dexter Holland, its ska stylings still manage to burrow into your brain and force you to smile. But the cover of Green Day's "Basket Case" is best ignored.

While 2003's export-ready "Nice" was patchy at best, "Splurge" sees Puffy settle into a new skin. They may never again shift a million singles, but Ami and Yumi are still having fun.