Ayuko Tsuchiya is a Japanese singer and voice actor born on July 3, 1977, in Shizuoka Prefecture. Her blood type is AB. She began her career in entertainment in 1995 under the different stage name Mami Yoshimoto, releasing the image song "Kagayaku Kioku no Naka ni..." for the game Emerald Dragon. Her path to voice acting was significantly shaped by winning both the singer and voice actor Grand Prix awards in an open audition held by the anime voice actor magazine Seiyuu Grand Prix. This achievement led to the release of her debut single, "Ato Sukoshi...", in 1999.

Tsuchiya made her debut as a voice actor in 2002, landing the role of the heroine Yuma Nanami in the planetarium feature Galaxy Express 999 for PLANETARIUM. This original story, supervised by Leiji Matsumoto, featured an esteemed cast including Masako Nozawa and Masako Ikeda. Her involvement with the Galaxy Express 999 franchise extended beyond the planetarium film. She performed in a live concert titled Ayuko Tsuchiya 999 LIVE "Heavy Melder's Saloon" in September 2002, where she sang songs from the planetarium production and other related tracks. She also voiced the character Yuma again in the web radio drama Yuma no Monogatari ~ Symphony No. V, which was based on the same story.

In addition to her work in the Galaxy Express 999 universe, Tsuchiya has taken on other voice roles. She played Tempestera in the 2004 television anime Ragnarok The Animation. Her portfolio includes numerous drama and voice dramas, such as parts in the Sweet Dragon III series in 2002 and the 2022 voice drama "Higashi no Orca". She has also contributed her voice to video game dubbing, including a role in the 2022 game Dying Light 2 Stay Human.

Music has remained a central part of Tsuchiya's career. She has released several singles and albums, and her songs have been used as theme music for various games. Notably, she traveled to Taiwan for the release of the game Miracle Garden, for which she performed the theme songs, being promoted as the first Japanese singer to work in the Taiwanese game industry. Her musical collaborations include working with renowned game music composer Ikuko Yamakawa on this project.

Much of Tsuchiya's later career has focused on educational and scientific content. She has narrated and performed theme songs for the "Kagaku no Tobira" documentary series and appeared in numerous other planetarium and astronomy-related programs. She has also hosted the web radio program Astro Radio. As of November 2018, she became affiliated with the agency PONTE after a period as a freelancer.