This collection documents the experiences and history of members of the Yabe family, a Japanese American family based in southern California in the decades prior to World War II. Much of the collection relates to Mitsuye (Jyoko) Yabe, who emigrated from Japan in the early 20th century, and to her daughters, particularly her youngest daughter, Miyuki (Yabe) Yasui. The materials reflect their lives before, during, and after their forced removal and incarceration at Heart Mountain Relocation Center in Wyoming, and date from the beginning of the 20th century through 2022. Most documents are in English; approximately one-fifth are in Japanese, including a portion in a pre-World War II script that is distinct from modern Japanese.

Series 1 consists of Mitsuye Yabe's correspondence, nearly all of which is written in Japanese and dates from just after World War II until her death in 1985. Most of the correspondence consists of incoming letters from various family members and friends, and is grouped roughly by correspondent. It has not been translated.

Series 2, Yabe family materials, contains original documents, such as marriage licenses, birth certificates, citizenship records, War Relocation Authority files for some individuals, and education-related materials. The school materials include report cards, certificates, and yearbooks, some of which are from Heart Mountain High School. The family materials also include a small number of letters among Mitsuye Yabe's daughters, Emi, Rayko, and Miyuki, as well as general family history documents. Mitsuye Yabe and Miyuki (Yabe) Yasui are the family members most represented in this series.

Series 3, Research files and historical writings, consists primarily of materials compiled or created by Miyuki (Yabe) Yasui about her family and the Heart Mountain Relocation Center. The materials are split into two subseries. Subseries 3.1 focuses on the history of the Yabe family, including the family's genealogy and origins in Okinawa. Individual histories explored in this subseries include Miyuki Yasui's grandfather Kentsu Yabu; her father, Kenden Yabe; and her mother, Mitsuye (Jyoko) Yabe. Subseries 3.2 contains research files on Heart Mountain, mainly in the form of copies of World War II-era government agency documents, such as weekly reports by the Heart Mountain project director, correspondence and other reports from or about Heart Mountain, and excerpts from the papers of two contemporary Wyoming governors and a senator.

Series 4 holds a selection of Yabe family photographs, mostly in black and white. A small number of photographs, consisting of group portraits and scenes from Kenden Yabe's funeral, predate World War II. Photographs taken at Heart Mountain, and particularly at Heart Mountain High school, show show Mitsuye, Rayko, and Miyuki Yabe during incarceration. Later photograph albums and scrapbooks depict late-life trips that Mitsuye Yabe made to Japan, as well as family reunions and other celebrations.