That's a join venture dominated by Softbank (that's also a cell phone operator, and owner of Sprint). Yahoo Inc. only holds 35% of it, and licences his name to

That's a join venture dominated by Softbank (that's also a cell phone operator, and owner of Sprint). Yahoo Inc. only holds 35% of it, and licences his name to this separate company. User accounts are separate too, if you create an account everywhere in the world but Japan it's a @yahoo.com account, but in Japan it's @yahoo.co.jp.