Apple Inc. (NASDAQ:AAPL) has been owning the Japanese smartphone market, but as Apple Insider’s Kevin Bostic points out, that could be about to change dramatically.

Apple japan

Shifting From Apple To Sony

Data from the research firm IDC indicates that the iPhone accounted for almost 40 percent of Japan’s smartphone sales during the first three months of the year. At that time, Sony Corporation (NYSE:SNE) (TYO:6758)’s smartphones made up a little over 13 percent of smartphone sales in Japan.

Bloomberg’s Mariko Yasu and Grace Huang reported on Thursday that Sony Corporation (NYSE:SNE) (TYO:6758)’s devices appear to be catching up rapidly. BCN, another research firm, said that within the last month, Sony’s smartphones made up about 36 percent of smartphone shipments in Japan. Meanwhile Apple Inc. (NASDAQ:AAPL)’s smartphone shipments fell to 25 percent in the Japanese market during the same four weeks.

The four weeks measured by BCN started May 6, and on that date, the firm said more than 40 percent of the Japanese smartphone market was made up of Apple’s iPhone. On that day, only 14 percent of the market belonged to Sony Corporation (NYSE:SNE) (TYO:6758). This means that in only a month, Apple Inc. (NASDAQ:AAPL)’s iPhone shipments in Japan have fallen off dramatically.

Apple Hurt By Sales At Sony

The biggest problem for Apple Inc. (NASDAQ:AAPL) right now is the big sales of Sony products. NTT DoCoMo, which is the biggest mobile carrier in Japan, offered promotions on only Sony’s Xperia line and Samsung’s Galaxy S4. About half of Japan’s mobile subscribers are on NTT DoCoMo’s network, which highlights how important it is for a handset maker to dominate it.

However, Apple Inc. (NASDAQ:AAPL)’s iPhone isn’t available on the network, even though it is the biggest Japanese carrier by far. Also it is the only carrier which doesn’t support Apple Inc. (NASDAQ:AAPL)’s products. NTT DoCoMo said late last year that it had a net loss of 40,800 subscribers because it did not support the iPhone. The carrier also said it would negotiate with Apple to come to an agreement to offer the company’s iPhone.

Sony Corporation (NYSE:SNE) (TYO:6758)’s takeover of market share on its home turf isn’t just hurting Apple Inc. (NASDAQ:AAPL). It’s also hurting Samsung Electronics Co., Ltd. (LON:BC94) (KRX:005930), which had a 13 percent share of smartphone sales in the week which started June 3. Both Apple and Samsung products are also likely being affected by the weak yen at this point, which is affecting prices on imported products.