Mitsui's 1722 house code barred any branch from dividing or selling its share, and the US occupation took the families' property in 1946

Mitsui Hachirobei Takatoshi, a merchant from Matsusaka in Ise, opened the Echigoya draper's shop in Edo and a buying store in Kyoto in 1673. He died in 1694 and left a will that set out the relations among the members of his family. His eldest son Takahira turned it into a house code in 1722, known as Sōchiku's will. The code made the family's assets a joint holding, the Omotokata, owned in fixed quotas by six head families and three related families. The main family held a little over 28 percent. Only the firstborn in each family could inherit. No family could ever withdraw, divide or sell its share; each received only its part of the profits. The code banned loans to feudal lords and speculation, and told sons to start as apprentices at 12 or 13. A revised constitution was adopted in 1900, and each male member swore an oath to it when he came of age. By 1940 the family had eleven heads. After Japan surrendered, the occupation ordered the zaibatsu dissolved. In October 1946 the Mitsui holding company and three others surrendered their securities to the Holding Company Liquidation Commission. Directive SCAPIN-1363 of 26 November 1946 placed the property of the Mitsui and nine other named families under the commission. The Mitsui companies regrouped in 1950 as a keiretsu, an alliance of firms, without family control.