Reiko Mutoh was a Japanese actress, voice actress, and narrator born on March 1, 1935, in Tokyo, Japan. She began her entertainment career as a child star, joining the children's theater group Group Robin. After graduating from high school, she successfully auditioned for NHK and began appearing in radio and television dramas during the early days of the television industry. Later in her career, she was affiliated with several talent management firms, including Theatre Echo, before ultimately joining Aoni Production, where she remained until her death.

Mutoh was renowned for her柔和甜美温暖 (gentle, sweet, and warm) vocal quality. This versatility allowed her to portray a wide range of characters, from可爱的少女 (cute girls) to成年女子 (adult women) and中年女性、老奶奶 (middle-aged and elderly women). She was particularly active and prominent during the 1960s and 1970s. A significant portion of her career was dedicated to Japanese voice-overs for foreign films and television series. She was the primary dubbing voice for major international stars like Elizabeth Taylor and Julie Andrews. A pivotal moment in her career came after the Japanese release of The Sound of Music; a comment from a young fan who said Maria's voice could not possibly be an "auntie" deeply affected her, leading her to focus exclusively on voice work and avoid public appearances to preserve the magic for children.

Mutoh's body of work in anime is extensive and includes many notable roles. She played the title character in Marvelous Melmo (known as Melmo Watari or Merumo) and Midori Azuma, also known as Swanee, in Casshan. She voiced Nono in New Moomin and took on the role of Sōi in Arei no Kagami. In film, her credits included Themis in Sea Prince and the Fire Child, Maya Rosenberg in Arcadia of My Youth, and Leader Laarela in the Queen Millennia movie. She also voiced Sara in The Door into Summer and Grandma Fumi in Rainbow Across the Pacific. Earlier in her career, she played roles such as Tomoko Okano in Otoko Ippiki Gaki Daisho and Kyoko in Kyojin no Hoshi. Her filmography also includes Michiru Sanjou in Attack No. 1, Akiko Yamato in Ai no Senshi Rainbowman, Chonko the Mouse in The Littlest Warrior, and Marie Antoinette in Étoile de la Seine. Later in her career, she focused primarily on narration work for television programs.

Reiko Mutoh passed away on October 29, 2006, due to acute heart failure at a hospital in Setagaya, Tokyo, at the age of 71. In recognition of her significant contributions and lasting impact on the voice acting industry, she was posthumously awarded the Special Achievement Award at the 3rd Seiyu Awards in 2009.