Sumiyoshi-kai
The Sumiyoshi-kai (住吉会), sometimes referred to as the Sumiyoshi-rengo (住吉連合, Sumiyoshi-rengō, "Sumiyoshi Union"), is the second-largest yakuza group in Japan with an estimated 2,200 members.Shops operating in these territories are often part of protection rackets in which they must pay a fee called a mikajime-ryō (みかじめ料).The Sumiyoshi-kai, as a federation, has a looser chain of command and while there is a chairman, some power is delegated to affiliate clan leaders.Police stated that they were probing for possible links between the murder and a series of shootings between the Sumiyoshi-kai and the Yamaguchi-gumi in neighboring Tochigi Prefecture.[9] Shūji Ogawa, who holds the position of kaicho, is the leader of the Sumiyoshi-kai at the time of Isao Seki's funeral.