Mio Ninomiya is a Japanese female voice actor affiliated with the talent agency Aptepro, having graduated from its 8th attached training school. She was born on May 28th in Nagano Prefecture. Her career includes a range of supporting roles in anime television series and original net animations. Notably, she voiced the characters Hachirō, a young Heijirō Kira, and Ume Ishiguro in the original net animation Ainu Teisōnin・ Kira Heijirō ～Ainu Nenoan Ainu～. She is also credited for the role of a young Siegwald Fitzenhagen in the fantasy comedy television series Endo and Kobayashi Live! The Latest on Tsundere Villainess Lieselotte. Her other voice work includes several minor roles in the multi-season anime My Next Life as a Villainess: All Routes Lead to Doom!, such as the Hunt family third daughter, a young lady, and a maid. Additional credits can be found in series like CUE!, Extreme Hearts, IDOLiSH7 Third Beat!, Management of a Novice Alchemist, and Trigun Stampede, where she typically lent her voice to child characters, students, or other ensemble cast members. Beyond acting, her listed hobbies and skills include handicrafts, singing karaoke, reading, and playing volleyball.