She graduated from Japan"s Bungakuza School of Dramatic Arts.
At the age of 12, she traveled to London to study dance at the Royal Ballet Academy. After 3 years, she returned to Tokyo. In 1971, Momoi debuted in director Kon Ichikawa"s Ai Futatabi (To Love Again).
Her career has spanned 35 years and over 60 films.
As an actress, she has worked with directors including Akira Kurosawa (Kagemusha, 1980), Tatsumi Kumashiro (Seishun no Satetsu, 1974), Yoji Yamada (The Yellow Handkerchief, 1977 and Otoko wa Tsuraiyo, 1979), Shohei Imamura (Why Not?, 1981), Shunji Iwai (Swallowtail Butterfly, 1996), June Ichikawa (Tokyo Yakyoku, 1997), Mitani Koki (Welcome Back, Mr McDonald, 1997), Yoshimitsu Morita (Like Asura, 2003) and Takashi Miike (IZO, Sukiyaki Western Django). She performed in The Sun (2005) directed by Alexander Sokurov and appeared in director Rob Marshall"s film Memoirs of a Geisha.
Momoi has pursued various projects in producing, directing, screenwriting, and design in addition to her acting. She has also released some 15 record albums as a singer and is an essayist.