The Universalist Japanese mission is one of those episodes in denominational history that perplexes those who might be interested in it. It flourished through the twenties, barely survived the War (I gather) but a single congregation of it -- the Doojin Christian Church, Tokyo (no Web site) -- remains today.
There's little one can read about it, but aha! I found 1890-1915: twenty five years of the Universalist Japan mission for download at Archive.org that fills in some details. Go thou and download.
And use it to prepare something for Japan Sunday in November (or not.)