The National Museum of Art (Osaka), The National Museum of Modern Art (Kyoto), Tokyo Metropolitan Art Museum, Hyogo Prefectural Museum of Art (Hyogo, Japan), The Museum of Modern Art New York, Museu de Arte Moderna do Rio de Janeiro (Brazil), Dallas Museum of Art (Dallas, Texas), etc.
Sadamasa Motonaga is one of the representative artists from the first generation of the Gutai Art Association. In his later career, Motonaga was also active as an author of children's books, and his speciﬁc style of humour is well known among people of all ages. Motonaga belonged to the Gutai group from 1955 to 1971. He developed innovative ideas such as 'Water Sculpture', which involves suspending vinyl bags ﬁlled with painted water. He also incorporated the traditional Japanese painting technique of 'Tarashikomi' into his style, using the airbrush to disperse acrylic paint, among other methods. Motonaga gained experience overseas from his early period, including contracts with the Martha Jackson Gallery (New York) and the International Centre of Aesthetic Research (Turin, Italy). Motonaga has received high acclaim in international exhibitions such as the Venice Biennial, Seoul International Print Biennial, Torino Premio Risone International Exhibition, and others.