Asahi Newspaper reports in Japanese,
http://www.tokyo-np.co.jp/article/na...002000108.html
Ministry of Land, Infrastructure, Transport and Tourism, and Tokyo city government are to improve the expression used in street signs in central Tokyo; street maps in Chiyoda ku and in Tokyo Metro stations.
From Romanization to English translation.
Example:
Sakurada Dori --->>> Sakurada Dori Ave.
Gaimusho. --->>> Ministry of Foreign Affairs
Kokkai --->>> The National Diet
more in the article
I don't think signs like "Kokkai" or "Gaimusho" have helped foreign tourists a lot.