Koshimizu has been an active voice actor since 2003, working on hundreds of roles on television animation, radio CDs, console games, pachislots games, and dramas over the years. She released a handful of singles and produced an album, Natural, on March 22, 2006.
Her notable voice acting roles include Kallen Stadtfeld from Code Geass: Lelouch of the Rebellion, Hojo Hibiki / Cure Melody in Suite Pretty Cure ♪, Nina Wong in Mai- 乙 HiME, Anemone in Symphony Eureka Eureka Seven, Yukiko in Persona 4 and the speaking role of Mikumo Guynemer, where she shared the role with JUNNA in Macross Δ. She has appeared alongside real-life idol group, Walküre during their Live events singing Ruchetto Arukan / Song of the Stars with JUNNA.
Koshimizu has voiced a variety of characters throughout her career, from boys to animals, but mainly focuses on young girls and adult women.
On February 28, 2018, she left her talent agency, Axl One management and announced that she would act as a freelancer.
- A Good Day To Think of Ami Koshimizu (Monthly Newtype April 2007 - March 2008)
- Ami Koshimizu's Twitter
- Interview: Ami Koshimizu and Mikako Takahashi Talk About Overseas Anime Fans and Events