Lodge 640 History 
By 1885, Masonry in Japan was firmly established within the foreign communities of Yokohama, Kobe, Tokyo and Nagasaki. For the next sixty years, however, it was to remain confined within these foreign enclaves and, with only a few notable exceptions, no Japanese citizen was to join the Fraternity.
In 1887 the Japanese Government passed legislation to control the activities of firebrand politicians opposed to the rapid introduction of Western ideas. The legislation banished influential leaders such as Yukio Ozaki and Tohru Hoshi from the capital and required police approval and supervision for all public meetings, both indoors and outdoors.
The legislation was eventually rescinded in 1898, and was no more than a minor episode in the turbulent political history of the Meiji Era. It was, however, to have a major effect upon the future of Masonry in Japan.
When the new law was passed, foreign Masons in Japan were, for the most part, unconcerned. Under international treaty, Japanese law did not apply to foreigners, and all criminal incidents involving foreigners came under the jurisdiction of a “Consuls’ Court” formed by a committee of consular officials residing in Japan.
In 1894, however, the United Kingdom and Japan signed a Treaty of Commerce and Navigation which, among other things, granted the citizens of each country full access, and hence full accountability, to the legal system of the other nation. With other countries expected to follow the United Kingdom's lead, the members of Masonic bodies in Japan began to feel concern for the privacy of their meetings.
They asked Bro. W. H. Stone, District Grand Master for the United Grand Lodge of England, to talk to the Foreign Minister of the Japanese Government, with the aim of obtaining permission to hold Masonic meetings without police supervision. Bro. Stone succeeded in obtaining this permission, but in return had to promise that the Masonic bodies would not admit Japanese citizens, nor would they have any contact with the Japanese community at large. The agreement was verbal.
The “Gentleman’s Agreement” continued until the commencement of the Pacific War in 1941.
[Based on Masonry vs the Japanese Government: The Gentleman's Agreement by MWB Saburo Katagiri, PGM of the Grand Lodge of Japan, with the permission of the author.]