Mina was born on March 24, 1997 in San Antonio, Texas, and grew up in Kobe, Hyōgo Prefecture, Japan. She moved to Japan when she was a toddler. Mina trained in ballet from a young age, having practiced it for over a decade before debuting with Twice. She attended Obayashi Sacred Heart School in Takarazuka, Hyōgo. In 2017, it was reported that Mina held dual Japanese and American citizenship. However, as of 2019, she no longer holds U.S. citizenship, as confirmed by the Quarterly Publication of Individuals Who Have Chosen to Expatriate published by the United States Internal Revenue Service, which lists the names of individuals who have lost citizenship in or before the previous quarter.