Mari Natsuki, born Junko Nakajima on May 2, 1952, in Tokyo, is a highly versatile Japanese performer whose career spans singing, dancing, live-action acting, and voice acting. She initially debuted as a singer in 1971 under her birth name before relaunching her career in 1973 with the stage name Mari Natsuki, which led to her breakthrough in the music industry. Her career is marked by a continuous evolution as an artist, driven by a philosophy of treating each new venture as a "rookie" and maintaining a curiosity that has led her to explore various facets of performance.

Natsuki's entry into the world of voice acting came through her work in theater. In 1990, following a period of artistic exploration in New York, she learned to market her work and sent a video of her experimental theater piece, "Inshōha" (Impressionist), to Studio Ghibli. This initiative led to her being called in for what would become her most iconic voice role. Director Hayao Miyazaki, after hearing her voice, created the twin characters of Yubaba and Zeniba specifically for her in the landmark 2001 film Spirited Away. This role brought her international recognition and demonstrated her powerful vocal range, a performance she would reprise decades later in the 2024 stage adaptation of the film, performing in both Japan and London.

Following the success of Spirited Away, Natsuki has continued to lend her distinctive voice to various anime and animated projects. In 2020, she voiced the character Mori Obaa-chan in the film Over the Sky. She also contributed to Wes Anderson's stop-motion animated film Isle of Dogs in 2018, providing the voice for the character Auntie. In addition to these roles, her voice work extends to video games, where she played Big Mama in the Japanese version of Metal Gear Solid 4: Guns of the Patriots and Katherine Marlowe in Uncharted 3: Drake's Deception.

While Natsuki has not been associated with a specific anime director or studio on a recurring basis in the same way as some full-time voice actors, her collaboration with Studio Ghibli on Spirited Away remains a defining partnership. Her approach to voice acting is informed by her extensive background in stage and screen. She has described the craft as a technical challenge that requires an actor to master elements like pitch, intensity, and tempo to imbue a character with presence, a discipline she finds both demanding and rewarding.

Throughout her long and varied career, Mari Natsuki has received numerous accolades that underscore her talent as a performer. She has been nominated twice for the Japan Academy Film Prize for Best Supporting Actress, winning the award in 2003 for her live-action role in the film Ping Pong. She also received the Minister of Education's Art Encouragement Prize for New Artists in 1984. Her contributions to the arts have been recognized with awards such as the Kinokuniya Theatre Award and the Montblanc International Culture Arts Award, reflecting her impact across both stage and screen.