Wikipedia
The (sometimes written Aizu-Kotetsukai or Aizu Kotetsu-kai), based in Kyoto, is Japan's fourth-largest yakuza organization. Its name comes from the Aizu region, "Kotetsu", a type of Japanese sword, and the suffix "-kai", or society.
Rather than a stand-alone gang, the Aizukotetsu-kai is a federation of approximately 100 of Kyoto's various yakuza groups, comprising an estimated 7,000 members.
In 1992 the Aizukotetsu-kai became one of the first yakuza syndicates named under Japan's new anti- boryokudan legislation, which gave police expanded powers to crack down on yakuza. Its chairman at the time, Tokutaro Takayama, campaigned publicly against the new laws, and the group launched a lawsuit challenging their constitutionality. In September 1995 the Kyoto District Court threw out the lawsuit.
In October 2005, the group formed an alliance with the Sixth Yamaguchi-gumi, Japan's largest yakuza clan now led by Kenichi Shinoda (Oyabun) and his second-in-command (Wakagashira) Kiyoshi Takayama.
In July 2014, an unaffiliated person known as "Oujo no ude" negotiated with Kiyoshi Takayama from Yamaguchi-gumi to form a new alliance between the largest syndicates, the most recent addition being the Kudo-kai.