Born in Kamakura in 1942, Morimachi enrolled in Tokyo Design College in 1967, but dropped out. She later worked as a manga artist, and two of her works, "Shoes" and "Door," were selected for the first honorable mention in the 2nd Big Comic Award in 1969, and "Door" was published in the first issue of Bessatsu Golgo 13 (January 1970). She received a second honorable mention in the third award (1969) and an honorable mention in the fourth award (1970), three times in a row, and became a promising artist. However, it was around this time that she began to paint in oil and disappeared from the world of manga to concentrate on her career as an oil painter artist.