She competed as an amateur boxer during this time, as well as while attending the Nippon Sport Science University, from which she graduated in spring of 2019.
[2] As an amateur boxer, Miyamoto most notably won the 2019 Japanese Women's National Championships in the bantamweight event and became the first women from the Mie Prefecture to win the national amateur title.
[3][4] Miyamoto made her professional debut against RINA in the opening preliminary bout of RISE 168 on May 28, 2023.
Miyamoto was able to knock her opponent down with a left hook in the final round of the bout.
[13] She won the fight by unanimous decision, with all three judges awarding every single round to her.