The problem between the San Francisco school board and the nation of Japan was solved by the Gentlemen's Agreement.
A gentlemen's agreement or gentleman's agreement refers to an informal and legally non-binding agreement between two or more parties.
The Gentlemen's Agreement of 1907 constituted a no formal agreement between the United States of America and the Empire of Japan by which the United States would not impose restrictions on Japanese immigration, meanwhile Japan would not allow more emigration to the United States.