Born in Tokyo, Japan, Mariko started playing piano at age five. While studying classical music, focusing on both piano and voice, she became increasingly drawn toward rock music. At seventeen she began writing songs. Together with two friends, Mariko formed a chorus trio for hire known as “Witches”. When that project ended she began picking up work singing jingles. She also joined a band in Tokyo, which included Roger Arnold on bass. This was the beginning of a collaboration which continues to this day.