Those are all strong and (at varying times) very innovative companies, but I don't see how any of them were positioned to be media companies in Japan. Sony owns a lot of media assets (ie Sony Pictures) but those are from M&A rather than something developed by the core business.

LINE is far more popular in Japan than WhatsApp. It's a Korean company, and if you mean why it never took off outside of Asia, I suspect its a matter of network effects, but I have not looked into it in detail.