These days more and more Japanese are using applications like Line to exchange short messages with each other. This is increasing in part because smartphone nu

These days more and more Japanese are using applications like Line to exchange short messages with each other. This is increasing in part because smartphone numbers are increasing rapidly and the "gala-kei" phones are dying out. In my experience the provider-based email addresses seem to be used mostly as a way to confirm other service's accounts, and that sort of thing. (An article with numbers supporting this: http://www.startup-dating.com/2013/02/smartphone-penetration-japan-iphone http://www.startup-dating.com/2013/02/smartphone-penetration...)