Born in 1952, Toyama Prefecture and graduated from the Design Department of Osaka University of Art, after working in a design company, Yoshimaru became independent and established Kokokumaru in 1984. Since 2002, he has concurrently been teaching at university. Working with his concept that graphic design itself is the culture that speaks of the times, he has been carrying out research into the visual expression of “human warmth” and has been producing works connected with this. Committed to linking design and culture, he participates in exhibition projects, sits on adjudication panels, and gives presentations. He has taken great personal interest in the packaging and publicity of patent medicines, and been involved in exhibitions and publishing on that theme.
Yoshimaru is a Visiting Professor at Osaka University of Art Graduate School and the Principal of Kokokumaru Co. Ltd. He is also a Member of the Japan Graphic Designers Association Inc., Japan Typography Association Inc., Tokyo Typo Directors Club and New York Type Directors Club.