Japanese company DeNA (the creator of infamous MobageTown here in Japan) bought US social games developer Ngmoco yesterday for $400 million. Founded 2 years ago by former EA executive Neil Young, Ngmoco develops iOS games (including We Rule, GodFinger and Flick Fishing) and boasts a social network of 13.5 million registered users named Plus+.

Apparently DeNA seeks to combine Plus+ with MobageTown, and use Ngmoco to develop games on different platforms in the US and Japan. DeNA projects record sales of $1 billion and seems intent on duplicating its extraordinary success in the US…