Several years ago, before the iPhone or any Android devices were available, weaboos lusted after Japanese cell phones (Wikipedia article), and capabilities and features they had that were unavailable in any cell phone on the market in North America.
It’s been years since I’ve seen an article about how wonderful Japanese cell phones are, and how those in the US and Canada are so deprived and backwards because none of the phones from Nokia, Ericsson or Motorola come close to the NEC Hello Kitty DoCoMo 6500 or whatever. With smartphones now the norm, more or less, do any Japanese cell phones offer features that still aren’t available on an iPhone or Android phone?
Short answer: there’s probably nothing on Japanese handsets that you want that you can’t get on an iPhone or Android phone.
The feature phones aren’t anything special, and ALL of the good smart phones are not Japanese. In fact, the best selling smart phones in Japan right now, besides the iPhone, are the Korean-made Samsung Galaxy line. As far as I know, no Japanese companies are developing smart phone OSs of their own. They’re all adapting Android.
For that reason, the US market is more likely to have the latest and greatest software. The hardware here also tends to have a very Japan-specific feature set, such as IC chip payment integration, TV reception, or character/brand integration (Disney tie-in phones have sold well lately). 99.9% of that either wouldn’t work outside Japan since it’s tied to native protocols or infrastructure, or it’s crap that no one outside Japan would care about other than to point out how odd/cute/pointless it is.
Longer answers: I wrote two articles on my blog touching on mobile technology in Japan. Why Apple isn’t Japanese, and Mobile Internet in Japan Spoiler: I’m not bullish on the Japanese tech industry.