Motonaga’s oeuvre, comprising paintings, objects, performances and stage art, ceramics, murals and installation artworks and picture books, is characterized by his humorous, enlivening (animating) use of biomorphic abstract shapes inspired by nature and manga cartoons, as well as the exploration of the materiality of color.
After leaving Gutai in 1971, Motonaga’s work again expanded beyond painting to ceramics, interior design, murals, and public performances and installation artworks, all of which he continuously developed around his signature-style of animated biomorphic shapes.
After the end of the Asian Pacific War, during which he worked for a munitions plant,[3]: 29 Motonaga resumed painting and engaged in the local art scene in the Hanshin region.
He received an award at the 11th Premio Lissone Internazionale per la Pittura in 1959 and held his first solo show abroad at the Martha Jackson Gallery in New York in 1961.
In 1966, Motonaga moved to New York to take part in a Japan Society’s residency program, joined by his partner Etsuko Nakatsuji, whom he had met in 1957 and lived with in Takarazuka since 1962.
[4]: 154 He expanded the range of his artistic production to ceramics, home furnishings (e.g. tapestries and chairs), murals, and installation artworks, which often included performative elements.
[4]: 154–155 He also began publishing picture books in collaboration with Tanikawa, who contributed onomatopoeic verses, while Motonaga provided illustrations with organic growth and movement of shapes as theme.
In the aftermath of the Great Hanshin earthquake in 1995, which devastated their home region, Motonaga and Nakatsuji engaged in reconstruction and rehabilitation projects with public art and events for children, such as the monument Yume–Kizuna (Dreams–Bonds) in the Nagisa Park in Kobe in 2001.
[8]* Transcending the thresholds of art genres, he also created small bio- and anthropomorphic objects from natural and everyday materials such as the stones that he covered in bright red, white and blue paint and adorned with wheat straws and looked like peculiar living creatures, which he submitted to the Ashiya City Exhibition in 1953 and 1954, or his anthropomorphic assemblages from colander, wire and wood, or the nail studded wooden poles that he covered in red paint.
[5]: 36 These works resonated with the trend of gesturally abstract Informel-style art in Japan in the mid-1950s, but, beyond the energetic visual effect of pouring paint, the procedure was not impetuous nor violent, but calm and controlled.
[3]: 33 His paintings around this time adopted a hard-edge style by emphasizing the flatness of his clear-cut phallic shapes, of which the contours were shaded in colorful gradations to produce the dynamic effect of glowing or shining.
Since the late 1970s, Motonaga, whose works continued to develop around the lives of his organic shapes, combined his diverse painting techniques, which he had explored separately until then, such as pouring, spraying, splashing, and drawing.
He also resumed to extend his work beyond painting by creating ceramics, home furnishings (e.g. tapestries and chairs), performances, murals, and installation artworks, including commissions for public buildings.
[7]: 13 In the 1990s the energetic intensity of his works achieved by his mix of methods and styles were amplified by Motonaga’s choice of large dimensions, by which he again expanded painting to performance, environmental and interactive installation art.
After his home region was hit by the Great Hanshin earthquake in 1995, Motonaga and Nakatsuji engaged in reconstruction and rehabilitation projects by creating public art and events for children,[4]: 157 including the seaside monument Yume–Kizuna (Dreams–Bonds) in the Nagisa Park in Kobe in 2001.