Emiko Koike was born into a family of artists and musicians, which perhaps explains her early inclination towards the creative arts. Growing up in Tokyo, Koike was exposed to a diverse range of cultural influences, from traditional Japanese theater to Western cinema. She began taking dance and piano lessons at a young age, which helped her develop a strong foundation in the performing arts. After completing her secondary education, Koike decided to pursue a career in acting, enrolling in a prestigious drama school in Tokyo.