By the latter half of middle period, bronze ware was intensively manufactured in Nakai and Hie sites at Fukuoka City, Fukuoka Prefecture and in Suku sites in Kasuga City.
中期後半までに青銅器の生産は福岡県福岡市那珂・比恵遺跡群や春日市須玖遺跡群などで集中的に行われるようになる。