After winning a special award at the "Next Generation Voice Actor Miracle Audition" held in 2017, Yui Ninomiya made her voice acting debut as Emma Hinata in the TV anime "Aikatsu Friends!” which began airing in April 2018. She also sang in the same anime.
On January 15, 2020, she made her debut as an artist on the Lantis label with her debut album "Love or Emotion.
Her hobbies are karaoke, visiting bookstores, rhythm games, reading, and deep reading of lyrics. Her special skills are playing the flute, calligraphy (first dan in brush writing/third dan in hard writing) etc.