TOKYO » The iPhone’s popularity in Japan is cracking open an industry long thought inaccessible to outsiders.

For years the typical Japanese cell phone — built to operate on a network hardly used anywhere else in the world — has been stuffed with quirky games and other applications that cater to finicky local tastes.

That helps explain why Japan’s mobile phone industry earned the nickname "Galapagos" — drawing parallels to the exotic animals that evolved on the isolated islands off South America — and why cell phones are called "galakei," which combines "keitai," the Japanese word for cell phone, with Galapagos.

Foreign developers of applications for phones didn’t give the Japanese market a second thought because of its insularity. But that is changing as the iPhone, for which tens of thousands of applications have been created, dominates Japanese smart-phone sales.

Everywhere one turns, on commuter trains and urban cafes, people are tapping away at their iPhone screens in a relatively rare Japanese embrace of technology that isn’t home-grown.

Azusa Furushima, a 22-year-old college student, who has an iPhone in a glittery Hello Kitty case, says she already has about 35 apps, including those for dieting and practicing typing.

American and other foreign developers for the iPhone now have eyes on this potentially lucrative market.

And Japanese users, thanks to galakei culture that has long had services that charged small fees, such as "i-mode," are used to paying for their applications.

"Japanese are well educated. They will pay for applications," said Brian Lee, a manager at Taiwan-based Penpower Inc., which sells an app for digitally organizing business cards. "A lot of developers are coming into this market."

Japanese developers, previously trapped into targeting galakei, in turn have a chance for a piece of the global iPhone pie, which topped 3 billion application downloads globally in less than 18 months, according to Apple. Apple takes 30 percent of the application sales, but the rest goes to developers.

Apple doesn’t give iPhone sales breakdowns by country. But Japan makes up a significant chunk of the 70 million iPhones sold worldwide so far, including a record 14.1 million last quarter.

Smart phones, mostly iPhone models that top sales rankings, make up 16 percent of Japanese cell phone sales of 35 million a year, according to Gfk Marketing Services Japan, which track such data.

Finnish developer Rovio Mobile, behind the "Angry Birds" game, which has racked up 27 million global downloads in a year, introduced a Japanese-language version a month ago.

The game, which features bubbly-headed, peevish birds that fight piglike creatures, has been No. 1 in iPhone games in the U.S. and 70 other nations. Hopes are high to move up from No. 6 to No. 1 someday in Japan as well.