Midori Kono Thiel was born in Berkeley, California on June 7, 1933 and spent her childhood in Lahaina on the island of Maui, Hawaii. She received her B.A. and M.A. in Fine Arts from the University of California Berkeley. A traveling fellowship from UC Berkeley allowed her to live for eighteen months in Japan where she studied woodblock printmaking with Un'ichi Hiratsuka and she considers Hideo Hagiwara her mentor. In addition she has extensive postgraduate studies in textiles, Japanese calligraphy, koto music and the performing arts of Noh and Kyogen.

Thiel has exhibited widely in California, Washington state and in Tokyo, and her work is represented in public and private collections in the U.S. and abroad. She is a resident of Washington and is Artist-in-Residence for Washington State Arts Commission, Seattle Arts Commission, and King County Arts Commission, and travels throughout the state teaching Japanese calligraphy and painting, and the culture of Japan. Thiel is a member of the Puget Sound Sumi Artists.