| March 1998 | In partnership, Yoshitaka Sonoda, as president, and Yoshinori Kobayashi founded the firm in Koto Ward, Tokyo, at the Time 24 Office Building. |
| May 2001 | Relocated to the Shinjuku Sumitomo Building. |
| December 2004 | Relocated to the Shinjuku Mitsui Building. |
| January 2015 | Firm divided into SONODA & KOBAYASHI Intellectual Property Law (Yoshitaka Sonoda as managing partner) and SONODA & Kobayashi IP SERVICES Inc. (Yoshitaka Sonoda as CEO). |
| January 2015 | Yumiko Tochino joined the Board of Directors for Sonoda & Kobayashi IP Services Inc |
| July 2015 | Akira Fujii, Toshiyasu Ishioka, Yoshitaka Togashi, and Kimio Sato joined as partners, Yoshinori Kobayashi serving as counsel. |
| January 2017 | Nicole Bigler joined the Board of Directors for Sonoda & Kobayashi IP Services Inc. |
| April 2019 | Harumi Kokaji joined as a partner |
| April 2019 | Yoko Nagatomo joined the Board of Directors for Sonoda & Kobayashi IP Services Inc. |
| April 2021 | Establishment of Sonoda & Kobayashi IP Group (Beijing) in China |
| November 2021 | Opening of a branch office in Beijing |
