According to the 1907 gentlemen’s agreement between the united states and japan,

The Gentlemen's Agreement of 1907 was an informal agreement between the United States and the Empire of Japan for which the United States ceased to impose restrictions on Japanese immigration, and Japan restricted emigration to the United States. The objective was to reduce tensions between the two powers of the Pacific Ocean. The agreement was never ratified by Congress, and was abolished in 1924.

The immediate cause of the agreement was the anti-Japanese sentiment that was beginning to emerge in California. In 1906, the California Board of Education imposed a regulation by which children of Japanese descent should receive classes in different schools, which involved racial segregation. At that time Japanese immigrants accounted for 1% of the population of California; many of them had also come under the 1894 treaty that ensured free immigration from Japan.

In the agreement, Japan agreed not to process more passports for Japanese citizens who wanted to work in the continental United States, which effectively eliminated any new Japanese immigration to America. In return, the United States agreed to accept the presence of immigrants already living on American soil, allow the immigration of their wives, children and parents and avoid legal discrimination against Japanese children in California schools.