In 1963, at age three, Mizoguchi began playing piano and later picked up the cello in 1971. He attended Tokyo National University of Fine Arts and Music from 1978 to 1985, where he studied violoncello. During his time there, he collaborated with Japanese pop-singers and worked as a studio musician for radio, TV, films, and albums. In 1982, at the age of 22, Mizoguchi experienced a serious traffic accident that inspired him to compose music. He released his first album, "Half inch dessert," in 1986 as composer, arranger, and performer. Since then, he has produced more than 20 albums, including motion picture soundtracks, performed in numerous concerts with ensembles or on his own, and is widely recognized as one of Japan's leading musicians by the late 1980s.