About japanese mobile phones?

Question:

In manga and anime you always see those big mobile phones, and the kids always ask another for their email address instead of their phone number. Now I know that manga/anime isn't always true but it seems odd that it comes back again and again. So now I was wondering how does this work?
I mean I saw some Japanese drama's and there they have those 'normal western' phones.
So what's the deal? Are those mobile phones in manga/anime just old? And can you only e-mail with those or something?

Just wondering :)

Thanks!

Answer:

Japanese phones are usually clamshell models that are tied to their respective carriers. Japan does not use GSM, which is why SMS does not work among cellphones of different carriers. Also a further drawback of SMS is that it only allows 60 full-width characters, far too short to write a message in Japanese.

To solve this problem, most Japanese phones come with a cellphone number, for calls obviously, as well as an email address, which is used for messaging. This is still the standard arrangement in Japan even as most phone networks are progressing on to 4G.

Normal western phones, like HTC and iPhone are sold in Japan as well. They too come with a cellphone number, and an email address for messaging purposes.