A gentlemen`s agreement, or gentleman`s agreement, is an informal and legally non-binding agreement between two or more parties. It is usually oral, but it can be written or simply understood as part of a tacit agreement by convention or by mutually beneficial label. The essence of a gentlemen`s agreement is that it depends on the honour of the parties for its achievement, rather than being enforceable in one way or another. It differs from a legal agreement or a contract. Japan was prepared to limit immigration to the United States, but was seriously injured by San Francisco`s discriminatory law, which specifically targeted its people. President Roosevelt, who wanted to maintain good relations with Japan as a pole opposed to Russian expansion in the Far East, intervened. While the U.S. ambassador reassured the Japanese government, Roosevelt summoned the mayor and the San Francisco school board to the White House in February 1907 and convinced him to end segregation and promised that the federal government itself would address the issue of immigration. On February 24, the gentlemen`s agreement was reached with Japan in the form of a Japanese memo, in which it was agreed to deny passports to workers wishing to enter the United States and to recognize the right of the United States to exclude Japanese immigrants with passports initially issued to other countries. March 13, 1907 followed the formal withdrawal of the San Francisco School Board`s decision. A final Japanese note, dated February 18, 1908, made the gentlemen`s agreement fully effective.
The agreement was replaced by the Immigration Exclusion Act of 1924. A report by the U.S. House of Representatives detailing its United States Steel Corporation investigation stated that in the 1890s there were two general types of associations or bulk consolidations between steel and ferrous interests in which different groups owned ownership, as well as a high degree of independence: the “pool” and the “Gentleman`s Agreement.”  The latter type lacked a formal organisation to regulate production or prices or forfeiture rules in the event of infringement.  The effectiveness of the agreement relied on members to meet informal commitments.  Gentlemen`s agreements have come to regulate international activities such as the coordination of monetary or trade policy.  According to Edmund Osmasczyk in the United Nations Encyclopedia and International Agreements, it is also defined as “an international term for an oral and unwritten but fully valid agreement.”  This type of agreement may allow a nation to circumvent national legal requirements to enter into a formal contract or it may be useful for a government to want to enter into a secret agreement that does not engage the next government.  According to another author, all international agreements are gentlemen`s agreements because, just before the war, they are all unenforceable.  Osmaczyk noted that there was a difference between gentlemen`s open agreements and secret diplomatic agreements.
 In the United States, in 1890, the prohibition of gentlemen`s agreements was introduced in interstate trade relations because the secrecy of these agreements was beyond anyone`s control.  In the automotive industry, Japanese manufacturers have agreed that no standard vehicle would have more than 276 hp (206 kW; 280 hp); The agreement ended in 2005.  German manufacturers limit the maximum speed of high-performance sedans (berlines) and breaks to 250 km/h.   When the Suzuki Hayabusa motorcycle exceeded 310 km/h in 1999, fears of a European ban or regulatory intervention led Japanese and European manufacturers to limit to 300 km/h at the end of 1999 See list of the fastest series bikes.