Mizue Ohtsuka is a Japanese voice actress and improvisational performer. She was born on March 21, 1968, in Fukuoka Prefecture. She is a graduate of Seikei University and the Engekijo theater institute. Throughout her career, she has used several stage names, including her birth name Mizue Ohtsuka, Mizuki Ohtsuka, and Mizue Ohtsuka, before settling on her current stage name. She is currently affiliated with KeKKe Corporation.

Ohtsuka's career began in the early 1990s, and she quickly became a familiar voice in anime. One of her earliest roles was in the OVA series Bad Boys, where she played Kaori Nakai. She is perhaps best known for her long-running roles in two major anime franchises: as Shinobu Kandadori in Crayon Shin-chan and as Nasuo Arai in Atashin'chi. Another significant role was as Nagi in the Tenchi Muyo! series, a character she voiced across multiple productions. Her other prominent anime roles include Giuliano in Romeo's Blue Skies, Kiraia in El-Hazard, and Sunya in The World is Still Beautiful.

Beyond anime, Ohtsuka has an extensive body of work in video games and foreign dubbing. She voiced Chizuru Ishigami in the Persona 2 games and provided the Japanese voice for the character Donna, the Yellow Ranger, in the live-action series Power Rangers and its film adaptation. She was also the first Japanese voice for Sarah Wiggum in the long-running animated series The Simpsons.

Throughout her career, Ohtsuka has demonstrated a recurring collaboration with the production teams behind the Crayon Shin-chan and Atashin'chi franchises, voicing her signature characters in numerous television episodes and feature films over several decades. A notable achievement in her later career is her work as an improvisational theater performer. She has been active in various stage productions and co-hosts a YouTube channel dedicated to interviewing other voice actors, showcasing her versatility and commitment to her craft beyond voice acting.