Smartphones outsold feature phones in Japan for the first time in February, according to research.
ComScore estimates that 19.3 million Japanese people, or one in five of the nation's mobile users, now own a smartphone.
Android has the lion's share of Japan's smartphone market, with a 61.4% slice. Apple has a comparatively smaller 34.2% share, but is itself Japan's eighth largest handset OEM.
Microsoft is trailing with a 3.9% share, down from 5.7% a year earlier.
The overall Japanese handset market is dominated by domestic brands, with the top five mobile OEMs being Sharp, (23.5% share) Panasonic (13.8%), Fujitsu (11.8%), NEC (9.7%) and Sony (7.5%).
More than half of Japanese handset users access email on their phones, and nearly one in five access social networking or blog sites.
ComScore Japan vice president Daizo Nishitani called smartphones overtaking feature phones by sales “an important shift in Japan’s mobile market.
“Japanese mobile phone users were already highly engaged with their devices, but with the added functionality and higher levels of mobile media consumption we should expect to see significant changes in behavior among the Japanese mobile population in 2012.”