Miigender is a xenogender in which a person feels that their gender is strongly correlated with Nintendo's Mii characters, or feels as though their gender is best described by comparing it with Miis. While the term was coined with neurodivergent individuals in mind, anybody can identify as Miigender.
Miigender is considered to fall under the umbrella of DS-Wiigender.
The Miigender flag's first design was posted to Tumblr on September 12th, 2019, on the same post where the term was coined.
The second flag, which is the widely used of the two, was created by the same person who coined the term as late as May 25th, 2020 and given updated meanings on June 30th, 2020. These were posted to the creator's old Twitter account, eqtnpgd.