This seems to be common misconception. Akihito is NOT "Emperor Heisei" now. The name is always given posthumously (though it is yet to be seen for Akihito if he

This seems to be common misconception. Akihito is NOT "Emperor Heisei" now. The name is always given posthumously (though it is yet to be seen for Akihito if he will be named immediately after abdication or also posthumously. It is severely rude simply because it implies that said person is already dead.