Especially rich in research potential, this main series of correspondence focuses on business matters, but its mixed contents reflect the wide range and interconnectedness of the Yasuis’ business transactions, community activities, and personal relationships. The majority of correspondence is in pre-World War II Japanese, and folder contents have been reviewed and summarized by translators; where feasible, the focus of individual folders has been noted in the folder title.

The series is divided into seven subseries: Subseries 1.1, Masuo Yasui business, community, and personal correspondence; Subseries 1.2, Yasui Brothers business and community correspondence; Subseries 1.3, Correspondence and related materials regarding incarceration and liquidation of assets; Subseries 1.4, Incoming Yasui Brothers correspondence; Subseries 1.5, Outgoing Yasui Brothers correspondence; Subseries 1.6, General Yasui Brothers business correspondence; and Subseries 1.7, Miscellaneous. (Personal and family correspondence is located in Series 6.)

The more personal and community-oriented correspondence in this series is listed first and covers a broad variety of topics, including assistance that Masuo Yasui provided to fellow Japanese immigrants, concerns about anti-Japanese sentiment, and a small quantity of material regarding the sale of the store and management of the Yasui assets by Ray Yasui during the family’s incarceration. Later subseries are more strictly business-related, consisting of correspondence between the Yasui Bros. Co. and its wholesalers, vendors, and customers. With the exception of correspondence about or during incarceration, business correspondence in this series roughly spans the period from the early dates of operation of the Yasui Brothers businesses to approximately a decade after their closing (1909-1951).