The Yamaken-gumi is a yakuza gang based in Kobe, Japan, founded in 1961 by Kenichi Yamamoto. It was the largest affiliate of the Yamaguchi-gumi until 2015, when it withdrew to form the Kobe Yamaguchi-gumi. In 2020 it became independent, and in 2021 it was welcomed back as the umbrella organization of the Yamaguchi-gumi. Membership dropped from an estimated 3,000-7,000 to around 800 after the split.
CRIMENET has extracted 19 linkages for this organization, including 2 cooperative ties across 2 organizations, 5 conflicts across 4 organizations and 12 other connections.