In 1966 he embarked on a long bicycle trip across Asia and Europe, eventually reaching Milan where he decided to permanently settle in 1968.

In 1979 he founded the Casa degli Artisti in Milan together with Luciano Fabro and Jole De Sanna.

Nagasawa's sculptures were made of materials such as paper, wood, stone and metal, and incorporated Eastern and Western cultural and religious elements.

He was invited to Documenta 9 in Kassel in 1992 and in 2006 he participated in the XII Biennale of Sculpture in Carrara.

He has also held solo shows at the Padiglione d'Arte Contemporanea in Milan (1988), the Galleria Comunale in Bologna (1993), and the Fundació Pilar i Joan Miró in Mallorca (1996).