| November 1968 |
Established Tamagawa Electronics Co., Ltd. as a limited company in Ota-ku, Tokyo, and commenced the development, manufacture, and sale of high-frequency circuit components. |
| May 1970 |
Reorganized from a limited company into a joint-stock company and relocated the head office and factory to Kohoku-ku, Yokohama. |
| April 1977 |
Relocated the head office and factory to Kamitsuchidana, Ayase-cho, Koza-gun, Kanagawa Prefecture. |
| April 1985 |
Constructed a new factory (Ayase Factory) in Kamitsuchidana, Ayase City, Kanagawa Prefecture, and strengthened the production system for measuring instrument products. |
| October 1994 |
Constructed a new head office and factory building at 3-11-23 Kamitsuchidananaka, Ayase City, Kanagawa Prefecture (current location), and relocated there. |
| August 1999 |
Registered the Company's shares with the Japan Securities Dealers Association for over-the-counter trading. |
| December 2004 |
Cancelled the over-the-counter registration with the Japan Securities Dealers Association and listed the Company's shares on the JASDAQ Securities Exchange. |
| October 2007 |
Changed the corporate name to Tamagawa Holdings Co., Ltd. through a company split and made Tamagawa Electronics Co., Ltd. a subsidiary. |
| April 2010 |
Following the merger of the JASDAQ Securities Exchange and the Osaka Securities Exchange, the Company's shares were listed on Osaka Securities Exchange JASDAQ (currently Tokyo Stock Exchange JASDAQ (Standard)). |
| September 2012 |
Established GP Energy Co., Ltd. as a subsidiary specializing in the operation of solar power generation projects. |
| February 2013 |
Established Tamagawa Solar Systems Co., Ltd. as a subsidiary engaged in the sales of solar power generation systems. |
| June 2013 |
Became effective as a Qualified Institutional Investor. |
| June 2013 |
Relocated the head office to Minato-ku, Tokyo. |
| April 2015 |
Subsidiary Tamagawa Electronics Co., Ltd. established TAMAGAWA ELECTRONICS VIETNAM CO., LTD. in Vietnam. |
| May 2015 |
Changed the company name from Tamagawa Solar Systems Co., Ltd. to Tamagawa Energy Co., Ltd. |
| June 2016 |
Acquired a 30% equity interest in Etrion Energy 5 G.K., making it an equity-method affiliate. |
| October 2018 |
Established THEG PTE. LTD. in Singapore. |
| March 2019 |
Subsidiary Tamagawa Electronics Co., Ltd. opened a Ho Chi Minh Office in Vietnam. |
| December 2019 |
Transferred all equity interests in Etrion Energy 5 G.K. |
| October 2020 |
Invested in TMY Technology Inc. (Taiwan). |
| April 2022 |
Following the review of market segments by the Tokyo Stock Exchange, the Company transitioned from JASDAQ (Standard) to the Standard Market. |
| October 2023 |
Subsidiary Tamagawa Energy Co., Ltd. established Tamagawa Insurance Co., Ltd. |
| October 2024 |
Changed the fiscal year-end (business year-end) to October 31. |
| October 2025 |
TAMAGAWA ELECTRONICS VIETNAM CO., LTD. constructed a new factory in Hung Yen Province and relocated there. |
