Using twitter from a Japanese mobile phone
I remember a few months ago when I tried in vain to login on Twitter from my Japanese ketai, which most have only a simple WAP browser (meaning no Javascript or complex CSS, old school webpages only). I couldn't get past the login form, which wouldn't clear for some reason.
Looks like this has been solved now, with the whole Twitter interface translated in Japanese, little Japanese keitai-only emoji and all. Some mobile-specific functionality has also been added, including emailing a tweet from your mobile (like mobile blogging found in some CMSs) and keypad menu selection.
That might explain why Twitter is becoming increasingly popular in Japan, after a slow start compared to other parts of the world. In fact, there is even a current drama on Japanese TV (Sunao ni narenakute, 素直になれなくて) about a group of friends who met using Twitter. A number of scenes showed the protagonists tweeting on their keitais, which I thought was not yet possible. Looks like I'm wrong.

Call center service said on 2011/03/22:
Now all the mobile are having the access with social networks and moreover,it could be reliable for the users.