Sure, but the transport part isn't relevant to what the GP is mentioning, which is that apparently Japanese etiquette requires you to write some amazingly long

Sure, but the transport part isn't relevant to what the GP is mentioning, which is that apparently Japanese etiquette requires you to write some amazingly long E-Mail. With a calendar invite all that's abstracted away and you just get "can you make it at such-and-such date at such-and-such time? yes/no/maybe".