User:ImperialMajestyIsWrong

This is the official website of the Imperial Household Agency

http://www.kunaicho.go.jp/eindex.html

Every single reference to the Emperor is "His Majesty the Emperor", while the rest of the imperial household retains their traditional style (e.g. His Imperial Highness the Crown Prince of Japan). There is no mention of this being an abbreviation, or anything other than the full and current style.

See also:

http://www.formsofaddress.info/Emperor.html

http://www.kunaicho.go.jp/e-about/history/history01.html

http://www.kunaicho.go.jp/e-faq/#FAQ01

Prince William addressing the Emperor as "Your Majesty" - https://www.youtube.com/watch?v=6rPUCEA3BPU#t=1m0s