Yahoo! Japan commented that the number of the active users is drastically decreasing recently, makes them difficult to maintain the service.
The end of the announcement page guided the users to migrate to three other communication services Yahoo! Japan provides, mobile messenger Kakao Talk (Yahoo! Japan jointly invested Kakako Talk Japan), free web mail Yahoo! Mail(which is again not the U.S. Yahoo! Mail) and recently released smartphone e-mail app Yahoo! Communication Mail.
The decreasing of the active users must be primarily by Line’s growth. mobile messenger service Line is taking 50 million domestic users.
LINE really dominates the chat/texting market in Japan. It will be hard for the other services Yahoo Japan participates in to catch up.