The Yūaikai (友愛会) or the "Friendly Society" was a pre-war Japanese trade union.
[1] It drew together industrial workers from Osaka and Tokyo during Japan's economic boom during World War I, and flourished from 1912 to 1918.
[2] It was the only large trade union to exist in Japan during this time period.
However, the organization only persuaded a few thousand women to join unions, compared to the 500,000 membership of the main group.
The Sōdōmei had a more radical political agenda, and was generally seen as more militant than the original group.