Momoko Kochi's remarkable journey in the entertainment industry began when she was discovered, alongside actors Akira Takarada and Yû Fujiki, in Toho's sixth annual New Face Contest in 1953. This auspicious start led to her immediate casting in her first film, A Woman's Heart Released Onna gokoro wa hitosuji ni, also released in 1953.
The following year, Kochi appeared in two films directed by the renowned Kajirô Yamamoto, a mentor who likely played a significant role in shaping her early career. It was likely during this period that younger director Ishirô Honda, who was also mentored by Yamamoto, discovered Kochi and chose her to play the female lead in his iconic film, Gojira, also known as Godzilla, in 1954.
Kochi's outstanding performance in Gojira led to typecasting in several more roles, both in monster movies and other genres, throughout the late 1950s. However, by 1959, Kochi recognized that her lack of formal training was hindering her ability to take on more challenging and better roles. She promptly began formal training, which marked the beginning of her transition to a stage career.
Kochi's stage career was soon bolstered by her appearances in TV commercials, allowing her to supplement her income. Although her film appearances became increasingly rare, her iconic role in Gojira continued to captivate fans, and director Takao Okawara wisely chose to reprise her role as Emiko Yamane, one of the sole survivors of the original film, in Godzilla vs. Destoroyah in 1995.
Okawara, who was accustomed to working with younger actors, was deeply impressed by Kochi's intense training and concentration abilities. As a result, all of her scenes were able to be wrapped in a single day, a testament to her dedication and professionalism.