During the early 1960s, his artworks radically transformed when he developed a hard-edge abstract style influenced by his interest in automobiles and contemporary urban living.

While he did not officially associate himself with any single artistic movement or group, he collaborated on multiple projects with his poet friends, Jean-Clarence Lambert and Makota Ōoka.

[3] Upon discovering the work of Jackson Pollock and Alexander Calder, Sugai was determined to continue his artistic journey in the United States.

Jean-Clarence Lambert, an art critic, poet and friend of the artist, recounts that Sugai's early life in Paris was a solitary one.

Speaking little French, he joined the community of Japanese artists living in Paris, including Toshimitsu Imai, Hisao Domoto, and the Japanese-American sculptor Shinkichi Tajiri, the last associated with the group CoBrA.

[1] : 14–15 Tajiri invited Sugai to exhibit in the second edition of art writer and critic Charles Estienne's salon Octobre held in 1953.

His work was admired by art dealer John Craven, who offered Sugai a contract with his gallery and his first solo exhibition in Paris.

Despite their increasing compositional simplicity that draws the eye in with an economy of assured strokes, the artist maintained a thick, textural quality in his use of paint.

[1]: 22 Sugai also created a number of sculptural works in the late 1950s, including Objet, a paintbrush mounted on a small plinth, englobed in paint and taking on an abstract aspect.

My experience of cold and Germanic rationalism led me to no longer consider my artworks as works independent from one another, but as an ensemble capable of being associated with society.

[2] The visual language of road signs and urban living, as well as the thrill and exhilaration of speed, would inspire Sugai for the rest of his life.

"[7] In an essay, the painter Ousami Keiji argued that Sugai's autoroute aesthetic allowed the artist to break away from the stereotypes of japonisme in order to impose his own identity.

[1]: 99  To aid him in his return to the studio, he hired an assistant, who began helping the artist prepare for his exhibition at the Japanese Pavilion of the Venice Biennale in 1968.

[1]: 126 In 1969, Sugai returned to Japan after 18 years of absence, having been commissioned to create a 16-meter long, 3.6 meter high mural in the entryway of the National Museum of Modern Art, Tokyo.