She began to study music at the Toho Gakuen School of Music of Tokyo and she continued in the USA at the prestigious Juilliard School and at the University of Yale. In 1967, when she was 24 years old, she won the prize of the Young Concert Artists (a corporation of New York of talent-scout ) and the second prize (1 prize not assigned ) at the ARD International Music Competition of Monaco di Baviera. The following year she obtained the same result at the international competition of Ginevra. She played in chamber music group with famous musicians such as Martha Argerich, Kyung-wha Chung, Heinz Holliger, Mischa Maisky, Midori Goto, Murray Perahia, Gidon Kremer, Yo-Yo Ma, Itzhak Perlman, Andras Schiff, Isaac Stern e Pinchas Zukerman. She performed as a solist with prestigious orchestras such as Berliner Philharmoniker, Orchestra reale del Concertgebouw, Symphonic Orchestra of Vienna, Philharmonic Real Orchestra of Stoccolma, London Symphony Orchestra, BBC Symphony Orchestra, Boston Symphony Orchestra and Chicago Symphony Orchestra. Nobuko Imai was a member of the Vermeer Quartet. In 2003 she founded the Michelangelo Quartet and she is a member with Mihaela Martin, Daniel Austrich and Frans Helmerson. She founded also the East-West Baroque Academy, a foundation to support Japanese and Dutch young musicians for the connection that the two states have during the centuries. From 1983 to 2003 she was professor of viola at the Hochschule fur Musik Detmold. At present she is teaching at the Conservatorium van Amsterdam, to the Escuela Superior de Musica Reina Sofia of Madrid , at the Ueno Gakuen University of Tokyo and at the Accademy of Kronberg. He also teached at the Haute ecole de musique of Ginevra and at the Academie of Musique “Tibor Varga” of Sion. She received numerous prizes and the Avon Arts Awars (1993), the Suntory Prize (1996) and the Mainiche Prize (1996). In 1989 the compositor Toru Takemitsu dedicated her concert for viola “A String Around Autumn” to her.
Since 1988 she is playing a viola of Andrea Guarneri of the 1690