Your point on Rakuten is fair.

However I believe Chinese companies have a strong edge regarding the messaging market. Chinese users are much more early adopters when it comes to messaging apps which enable Alibaba or Tencent to test new ideas much faster. Now that competition is getting fierce in China, they are expanding aggressively elsewhere and thus bring their deep expertise in the messaging market to the US.

Tango's CTO Eric Setton just got $250M from Alibaba praised this strategic move saying that tapping into Alibaba will “bring a crystal ball into (their) boardroom… Asia has insight that is around a year ahead of the West right now” (http://thenextweb.com/mobile/2014/03/20/chat-app-tango-raise...)