Born in Mie in 1922, Motonaga is best known as a key member of Gutai Art Association, an avant-garde artist collective founded in 1954.
Having originally trained as a manga artist, and worked as a newspaper illustrator, he began to turn toward fine art in the late 1940s. He was invited to join Gutai by Jiro Yoshihara in 1955, and became known for his experimental performances, installations, and paintings. In 1958, he invented a painting style inspired by the traditional Japanese technique called tarashikomi, which involved pouring different colored paints one upon another before the pigment is fully dry to achieve a dripping effect. Motonaga’s paintings are thus characterized by bold and organic forms and textures that playfully balance intention and intuition, control and chance. In the 1960s, he presented his work abroad in Europe and the US, and was invited for a residency in New York in 1966. There, he began experimenting with airbrushes and acrylic paint, which led to his transition to a more contemporary, flat style - evocative of graffiti and animation. In the 1970s he expanded his practice to include printmaking, stage design, and children’s books.
Motonaga’s work has been shown in many exhibitions at home and abroad, including the large retrospectives held at Mie Prefectural Museum of Art in 1991 and 2009. He passed away in Hyogo in 2011.