iPhone sales rankings in Japan as reported by the bcnranking.jp website. Apple took the first 6 places in March, 2014
I checked some of my clients’s websites and found that about 60% of mobile visitors had an iPhone. Contrast this to Samsung’s 5%. There are many reasons for this–some historical–but that is not what is important for Internet marketing.
When you optimise for mobile in Japanese, make sure the website works well on the iPhone.