In Japan, a strong alliance of related organizations that shares knowledge and cooperates to control its sector of the business, including the supply chain and distribution. Meaning "series," the "horizontal" Keiretsu are six major banks, such as the Mitsui Group and Sumitomo Group. "Vertical" Keiretsu are industry consortia, such as the Toyota Group, Honda Group, Hitachi and Toshiba. The Japanese government is involved and supportive. See interfirm network.