What is Rakuten Link? An easy-to-understand explanation of how Rakuten Mobile calls become free and points to note

I heard that calls are free with Rakuten Mobile, but is it really free no matter who I call?From calls to family and friends to mobile phones from other carriers, landlines, inquiries to shops, and ...

[Rakuten Mobile Usage Tips] A few months after switching from povo. The "blind spot-free" calling environment achieved with Android and dual SIM

For a long time, I maintained my main line (the phone number I give to family and friends) on au's online-only plan, "povo ...