Miki Ōtsu started learning to play electronic organ at the age of six. She liked to sing from an early age and was willing to go into music in the future. During her adolescence, she began to write her original songs as if she had written a diary about her feelings that she could not tell anyone.
In 1997, a demo tape triggered her debut as the vocalist for a commercial for "JR Tokai - Shisendo -". Her singing created a sensation that it didn’t just stay in Japan. She received high praise overseas as well and won a finalist for International Broadcasting Award. Since then, she has continued to be highly valued, producing songs as a lyricist, composer, and singer for many singers, animations, and games including more than 40 commercials and "Bokura ga Ita", "Sayonara, Zetsubou-Sensei", and "Gokujo Seitokai", and many of which were ranked high on the charts.
In 2001, the single produced by musicians living in L.A., "Rain Slipping Through Fingers" and "Send Back to the Sky", was released. The CD features the jacket (CD booklet) designed by art director Yukio Abe, who is highly regarded both in Japan and overseas. Around the same time, a collection of her poems featuring illustrations by him was released. In 2006, she released a new song, "Rather than Counting the Stars" which was inserted into the TV animation of the popular comic "Bokura ga Ita" and it attracted attention in the foreign media.
Besides, Miki Ōtsu continued to work energetically with various artists such as illustrator Saori Tanabe, producing collaborative works, performing lives, and conducting music education activities. Due to her repeated illness, she temporarily stopped her activities, but she positively resumed her activities in 2020.
Her clear singing voice with warmth and strong appeal, the world of lyrics that beautifully depicts the sensitivity of people's hearts, and the melodies that are stuck in our heads continue to touch the heart of many people.