Yahoo! Japan announced [J] that it would terminate its messenger service “Yahoo! Messenger” at 3 p.m. on March 26, 2014.
Yahoo! Messenger was one of the most popular messenger services for Japanese Internet users, competed against Skype and MSN Messenger. (MSN Messenger, aka Windows Live Messenger, was also stopped after Microsoft got Skype)
Yahoo! Japan and U.S. Yahoo! are/were not the same company, used different account system. As a result of that, Yahoo! Messengers are also different between English and Japanese, which means English Yahoo! Messenger users could not chat with Japanese Yahoo! Messenger users, different from MSN Messenger and Skype.
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.