Japan's smartphone users have surged 43 percent this year, and two-thirds now use Android devices, according to a survey conducted by comScore.
The market researcher said it polled over 4,000 Japanese mobile phone users for the April to June period, and found that 64 percent of the country's 24 million smartphone users now use Android devices, versus 32 percent who use iOS.
Microsoft's operating systems were a distant third at 3.2 percent.
While the comScore data shows Apple's share of the OS market is slowly slipping, other data has showed its hardware share is still strong. Local research firm MM Research Institute has said that in the year through March, Apple was the clear winner in Japan for smartphones, with a 30 percent share.
Two of Japan's big three operators, au and Softbank, now offer the iPhone, while all offer a bevy of Android devices, including many made by Japanese companies. Domestic manufacturers have little presence overseas apart from Sony, but are still a major force within the country because they offer many features for local users, including built-in train passes and receivers for the mobile TV broadcasts.
The research firm said Sharp is the clear market leader in the mobile handset market, including both smart and feature phones, followed by Panasonic and Fujitsu.
The company also researched how Japanese subscribers user their phones, and found that the most common use was taking photographs, followed by email.
The data also showed that more people in Japan say they use apps than their mobile browser, 55 percent versus 51 percent.
Mobile email has long been a standard feature in the country, and the survey showed just 47 percent of respondents had sent a text during the month they were polled.
All three of Japan's carriers are now pushing smartphones, offering discount plans and unlimited voice to get people to switch over from feature phones. Manufacturers like Fujitsu have developed smartphones aimed at the elderly, with large text and touch screens that sense false taps, while companies like Sharp have rolled out hybrid phones, with smartphone hardware along with traditional mobile phone keypads.