Apple Inc. is striking gold in an unlikely place: Japan.

In the past two years, Japan has emerged as Apple's fastest-growing region, far outpacing its home market and the booming economies of Greater China and the rest of Asia. Japan is also home to Apple's biggest profit margins, and the only one of Apple's five regions where operating profit grew in the past fiscal year.

That is surprising because Japan isn't most companies' idea of a growth market. It has labored through two decades of economic malaise, and is saddled with a shrinking, aging population. Moreover, domestic firms that pride themselves on consumer electronics have kept foreign competitors at bay for decades.

The iPhone has propelled Apple's success in Japan, supported by heavy marketing and rich subsidies from telephone companies. The iPhone's cachet taps Japan's fervor for brand-name goods, similar to how Japanese shoppers once flocked to Louis Vuitton bags and Burberry scarves.

"Apple's brand is just overwhelming here," said Eiji Mori, a Tokyo-based analyst at BCN Inc. "It's not about specifications. It's not about rationale. It's about owning an iPhone."