Kōchi was discovered in 1953 in Toho's New Face Contest. By the late 1950s she found herself typecast into science fiction and horror movies. She decided to pursue formal acting. In the 1960s she was on stage doing Shakespeare. She also did occasional television commercials. She didn't act in movies again until 1995. Kōchi died at age 66 in Tokyo Japan on November 5, 1998 from intestinal cancer. 