Returning to Japan from the US in 1969, Igarashi set up his own studio with some friends. In the early years, commissions were scarce, and he combined his design work with writing and editing assignments, including several articles for the Japanese magazines, Graphic Design and Katei-Gaho. Gradually, the design projects picked up, and Igarashi embarked on what is considered to be his most representative alphabet works. His lettering appeared on magazine covers, posters, and record sleeves.
Key to Igarashi’s growing success was his strategic streamlining of communications. He quickly established a PR department with English-speaking staff and furnished the office with the necessary technology to get his designs and message distributed. Certainly, the widespread recognition of his motif of choice – the alphabet – also helped his international reach.
A special feature on Igarashi in the 1979/80 edition of Swiss magazine Graphis brought his work a whole new audience. He became a member of the Alliance Graphique Internationale (AGI), and became more actively involved with designers from various countries – including Alan Fletcher and Massimo Vignelli. Now on an even footing, he began to participate in the Western graphic design he’d so long admired.
From 1984 to 1991, Igarashi worked on his famous calendar posters for the Museum of Modern Art in New York. The project included 622 individually-designed numerals to represent the 365 days of the year. Over the seven years, he designed 4,536 variations of axonometric three-dimensional numerals, based on 84 different ideas.