THE WALL STREET JOURNAL posted the information that Rakuten working to open a new gaming platform first in Japan.
The company already tried to enter into the app store business with the Rakuten AppStore but will be closed in this December.

According to the article the platform will be a browser based one which is not going to depends on iOS or Android so it will be a DMM.com like service.
What is not clear (next to the exactly business model) is the service will be available in all regions or just in Japan.