While the Dai-Ichi Kangyo Bank Group is consider the newest of the Big Six horizontal keiretsu, the main bank was created from Dai-Ichi Bank (First National Bank) which was the core of a zaibatsu created in the Meiji Era. The Dai-Ichi Bank also had ties to two other zaibatsu, Furukawa and Matsukata (which included the Kawasaki firms).

Dai-Ichi Kangyo Bank was formed in 1971 by the merger of Dai-Ichi Bank and Kangyo Bank. Since then it has assimilated a loose-knit keiretsu which includes many of the firms originally parts of the Furukawa and Matsukata zaibatsu. The Kangyo Bank also brought associates to the DKB keiretsu.