It was big news that Zynga purchased Japanese startup Unoh (Unoh means the right brain in Japanese).
Overseas people are interested in Unoh's social games. But, unfortunately they can't play those games. Because those can play with a Japanese mobile only from Japan.
Unoh administers a mobile social games in mixi, MobageTown and GREE.
"Machitsuku" (means the "build the city" in Japanese) for mixi mobile & MobageTown
"Band yarouyo!" (means the "Let's play with BAND" in Japanese) for mixi mobile
"Minnade Omikuji" (via Wiki) for mixi mobile
"Kaizoku chronicle" (means the "pirate chronicle" in Japanese) for GREE mobile
Especially, Machitsuku mixi ver. is popular very much, and more than 3,000,000 mixi users play.
In Japan, it's everyday scenery to play a game with a mobile.
By the way, In 2008, I examined whether there were mobile avatar SNS & online game portal site(such as Japanese MogageTown) in abroad. But I can't readily found. There were only Sulake's Mini Friday & Ironstar Helsinki's MoiPal. Are there mobile avatar SNS elsewhere?