March 1998In partnership, Yoshitaka Sonoda, as president, and Yoshinori Kobayashi founded the firm in Koto Ward, Tokyo, at the Time 24 Office Building.
May 2001Relocated to the Shinjuku Sumitomo Building.
December 2004Relocated to the Shinjuku Mitsui Building.
January 2015Firm divided into SONODA & KOBAYASHI Intellectual Property Law (Yoshitaka Sonoda as managing partner) and SONODA & Kobayashi IP SERVICES Inc. (Yoshitaka Sonoda as CEO).
January 2015Yumiko Tochino joined the Board of Directors for Sonoda & Kobayashi IP Services Inc
July 2015Akira Fujii, Toshiyasu Ishioka, Yoshitaka Togashi, and Kimio Sato joined as partners, Yoshinori Kobayashi serving as counsel.
January 2017Nicole Bigler joined the Board of Directors for Sonoda & Kobayashi IP Services Inc.
April 2019Harumi Kokaji joined as a partner
April 2019Yoko Nagatomo joined the Board of Directors for Sonoda & Kobayashi IP Services Inc.