After winning the third season of the Japanese reality television series and MMA competition Fighting Agent War in 2018, Hirata earned a contract with ONE and made her professional debut in 2019.
[3] With dreams of competing in the Olympics, she took third place in a national competition in fifth grade, and later won a prefectural judo championship in high school.
[5] It was during this time that Hirata started watching and became interested in mixed martial arts (MMA), which she thought looked fun and much freer than the "strict" rule-based judo.
[6] Hirata then competed in the third season of the AbemaTV reality TV show and MMA competition Fighting Agent War (格闘代理戦争, Kakutō Dairi Sensō), where she was coached by Hayato Sakurai and won all three of her bouts by submission.
[3] Hirata defeated Shinya Aoki's fighter Mizuki Furuse in the finals on December 29, 2018, via Americana submission in the first round to earn 3 million yen and a professional contract with ONE Championship.
[19] In May 2022, Hirata and her brother were some of the first fighters to take part in AbemaTV's Kaigai Musha Shugyō Project (海外武者修行プロジェクト), a program documenting young Japanese mixed martial artists that are given the opportunity to train at top-level MMA gyms in North America.
[21] After Hirata missed weight and failed the hydration test, the match was contested at a catchweight of 54.0 kg and she forfeited 50% of her fight purse to Lin.
[25] Hirata was scheduled to face Seo Hee Ham at ONE 163 on November 19, 2022, with the winner expected to receive a shot at the atomweight championship.
[27] In January 2023, AbemaTV aired a program on Hirata that stated she flew to Japan in November 2022 after abnormalities were detected in her kidneys and liver during a medical checkup for the Ham fight.
[28] Although no abnormalities were detected in Japan, the doctor told her to take a break due to a hormone imbalance and to see if the weight cut had any further adverse affects.
[41][42] She has also trained with Shinya Aoki, whom she has called the greatest Japanese mixed martial artist and cited as a role model for being oneself without worrying about the cameras.