Samsung, being a South Korean company, unsurprisingly enjoys massive success in their home country, and while they experience something similar across the globe - particularly in North America and Western Europe - there's one market they just can't crack. That market is Japan, which might be a small country, but is an important market for smartphone manufacturers and one that is dangerously close to becoming Apple's and Apple's alone if someone can't break in. Sony is doing pretty well in Japan, which is nice to see the company succeed at home.
Samsung however, have experience poor sales after poor sales. The Galaxy S5 was launched in the region as the Galaxy J, in order to appeal better to the Japanese audience. With the Galaxy S6 and Galaxy S6 Edge, Samsung completely removed their branding from the device. There's no Samsung logo around the back, simply a "Galaxy" logo as well as the network branding. It could be argued that Samsung felt it wise to remove a South Korean company's name from the device in order to steer clear of tensions between the two nations, but whatever the reason it has had no effect.
According to Business Korea, Samsung is continuing to struggle in Japan, and research firm BCN have said that the Galaxy S6 Edge was ranked 26th in weekly sales from April 27 to May 3. Meanwhile, Apple has 6 models in the top 10 smartphones sold in Japan. This doesn't compare favorably with a spot in the top 5 smartphones in the UK, and the massive pre-order numbers elsewhere across the globe certainly didn't translate to success in Japan.
For every market that you'e going to be successful in, there's always going to be a weak point, and it looks Samsung has finally found theirs. Japan has not been a kind market to Samsung, and it looks like writing is on the wall for Samsung to leave the Japanese smartphone market. The question is whether or not Samsung is content to sell devices in Japan with dismal results, or will they swallow their pride and give up? If something doesn't give soon, they might find it difficult to persuade networks like NTT DoCoMo and KDDI au from carrying future devices.