Marie and her husband, Takumi Kawahara, were married in 2012. Both Marie and Takumi were born in 1984 in Osaka, Japan.
While the pair haven't revealed many details about their relationship, Marie told Good Housekeeping in 2016 that "fundamentally speaking, we're in the same groove" and that he "was able to clean and be very organized even before he read my book, but it was certainly even more pronounced after he read my book. He became even more efficient."