The Founder's Precepts “Monjuin Shiigaki” is a letter sent by Masatomo Sumitomo (1585-1652), the founder of Sumitomo and a religious man, to his family members in his old age. It succinctly describes the guiding principles of his business operations.

At the beginning, it urges the reader, “Not only in matters of business but in all situations, make efforts with deepest gratitude in every aspect.”

The precepts also include such teachings as, “When goods are offered to you below the normal market price, under no circumstances should you ever purchase such goods, for their origins are unknown and they are probably stolen property,” “Never give shelter to a stranger, no matter who it might be; also, never take a stranger's goods into your custody, no matter how innocent they might appear” (these acts were prohibited by the government), and “No matter what someone might say to you, never lose your temper or speak harsh words; politely explain your position until an understanding can be reached.” These teachings have been handed down and form the basis of Sumitomo's business philosophy. They are still seen in today's principles, such as “no pursuing easy gains” (i.e., only making a profit on a fairly priced transaction that can be explained with confidence), “compliance” and “integrity and sound management.”

The Besshi Copper Mines (opened in 1691) encountered many adverse conditions during the Meiji Restoration (in the late 1860s). When the price of copper fell, operating costs increased sharply due to rising prices of rice and other items, and loans to the feudal lords were uncollectable. At one point, it was almost forced to sell out. Saihei Hirose (1828-1914), manager of the mines who later became Sumitomo's first Director-General, acted boldly and modernized the operation with Western style technologies.

Hirose's operational reforms saved the mines and its community.

In 1882, when serving as Director-General, Hirose formulated the Rules Governing the House of Sumitomo, which consisted of 19 sections and 196 articles, to reflect the business philosophy the family had followed over its 250-year history. The Rules clearly illustrate Sumitomo's corporate philosophy in Article 3, Section I: “We shall practice sound management in order to cope effectively with the changing times. Under no circumstances, however, shall we pursue easy gains or act imprudently.”

In 1891, the Rules Governing the House of Sumitomo were separated into two parts, the family code (corporate rules) and the family constitutions (the principles of the family head), to distinguish ownership from business operations. On that occasion, the principle of “integrity” was introduced and placed at the beginning of the Rules Governing the House of Sumitomo with the principle in Article 3, which then together became the Business Principles. In 1928, while Sumitomo's business expanded into a variety of areas, including the steel, machinery and chemical industries, Sumitomo's Business Rules were established. The two articles of the Business Principles have been passed on for generations and still serve as the corporate rules of all group companies.

Article 1: Sumitomo shall achieve strength and prosperity by placing prime importance on integrity and sound management in the conduct of its business.

Article 2: Sumitomo shall manage its activities with foresight and flexibility in order to cope effectively with the changing times. Under no circumstances, however, shall it pursue easy gains or act imprudently.

Sumitomo Corporation Management Charter

The Osaka North Harbour Company Limited, the predecessor of Sumitomo Corporation, was founded in 1919. Later, after World War II, the company changed its name to Nippon Engineering Co., Ltd., starting a new life as a general trading firm. In 1952, when the company was incorporated with the current name, the Business Principles were chosen as the management philosophy for all corporate operations and the foundation to sustained growth.

While Japan's economy was growing rapidly after the war, environmental pollution, inflation and other public issues started to arise. Business corporations and their codes of conduct were challenged to make clear the relationship between the national government and corporations, as well as between citizens and corporations.

To respond to this, in 1973, Sumitomo Corporation laid down the Sumitomo Corporation Management Charter, an original charter that consists of the Basic Principles of Management and the Operational Guidelines.