Born in Niigata Prefecture, Miwa graduated from the Kyoto Municipal School of Fine Arts and Crafts in 1921, continued his studies with Domoto Insho (1891-1975) and took a second degree in 1924. His work was shown and awarded prizes in the Teiten exhibitions of 1927 and 1931. After the war he painted traditional bird-and-flower paintings and in 1959 he became a member of the Nitten. In 1962 his work won an award at the Shin Nitten exhibition. He became a member of the Japan Art Academy (Nihon Geijutsuin) in 1979 and, at this time, his work broadened in scope as he designed stage sets and temple frescoes. In 1981 Miwa's work was shown in the Ginza Matsuya department store in Tokyo.