There are three major cell phone companies in Japan: Softbank (the only provider of the iPhone), NTT docomo (provider of Samsung’s Android phones), and au (by KDDI). Softbank is generally perceived as the company for non-Japanese, but whether tha. Jan 14, 2018 I don't believe there is to update to android 5.1 is not the problem, the problem is (i think) that you first have to update the software from NTT docomo network (Settings-Device Management-About Phone-Software Update) (meaning you will have to bee in japan and using their network) and after that you can do the android update even outside Japan (Settings-Device Management-About Phone.