| 1973年05月 |
Y.A.C. Co., Ltd. was established at Akishima, Tokyo with a capital of 2.1 million yen. |
| 1973年06月 |
Penetrated into industrial package business and started to sell packaging equipment to food industry and cleaning industry. |
| 1975年08月 |
Corporate head quarter moves to Tachikawa City, Tokyo |
| 1976年05月 |
Builds Akishima factory at Akishima-Shi, Tokyo. |
| 1977年07月 |
Penetrated into semiconductor business. |
| 1982年05月 |
Built a headquarter factory at Akishima. |
| 1984年02月 |
Developed and started to sell POS system for liquor store |
| 1985年08月 |
Started magnetic memory disk business. |
| 1988年07月 |
Corporate main factory extends floors |
| 1991年04月 |
Opens California Representative Office at Santa Clara, California |
| 1992年03月 |
Builds Technical Center at Akishima City, Tokyo |
| 1994年06月 |
Started to traded on counter of Japan Securities Dealers Association (present “JQ”) |
| 1995年10月 |
Established YAC Systems Singapore Pte. Ltd. at Singapore with a capital of S$300 thousand. |
| 1997年11月 |
Builds the 2nd Akishima Factory |
| 2000年04月 |
Merged with Plasma System co., Ltd. |
| 2001年10月 |
Purchases industrial laundry equipment business from Fuji car Mfg group |
| 2006年08月 |
Acquires and consolidates Yoshimura Machinery Co., Ltd and changes the corporate name to YAC Niigata Machinery Co., Ltd. |
| 2006年10月 |
Listed on TSE2. |
| 2007年12月 |
Listed on TSE1 |
| 2009年05月 |
Purchases Photo Voltaic business from S.E.S. Co., Ltd. |
| 2009年12月 |
Establishes subsidiary in Korea. |
| 2010年05月 |
Established YAC (Shanghai) International Trade Co., Ltd. in Shanghai, P.R.C. . |
| 2011年04月 |
Acquired and consolidated Denko Co., Ltd. and changed name into YAC Denko Co., Ltd. |
| 2012年01月 |
DENKO Co., Ltd. changes corporate name to YAC DENKO Co., Ltd. |
| 2013年03月 |
Acquired and consolidated Kokusai Dennetsu Co., Ltd and changed name into YAC Kokusai Dennetsu Co., Ltd. |
| 2013年11月 |
Acquired and consolidated Ohkura Electric Co., Ltd. |
| 2014年06月 |
Established YAC Dastech Co., Ltd. |
| 2014年07月 |
Acquired and consolidated Pheton Co., Ltd. and changed name into YAC Pheton Co., Ltd. |
| 2014年11月 |
Established Shaoxing Weiaixin Electronic Equipment Co.,Ltd. |
| 2015年07月 |
Acquired and consolidated Nihon Garter Co., Ltd. |
| 2015年10月 |
Established T.Y.A.C.CORP. |
| 2016年01月 |
Merged with YAC Phoeton Co., Ltd. |
| 2016年09月 |
Acquired and consolidated Miyuki Elecs Co., Ltd. |
| 2017年02月 |
Acquired ion beam application equipment manufacturing business from Hitachi Ibaraki Technical Service Ltd. |
| 2017年04月 |
Transition to holding company system and changed name to Y.A.C. HOLDINGS CO., LTD. |
| 2018年04月 |
Built Fuji factory at Minamitsuru-Gun, Yamanashi. |
| 2019年04月 |
Started Business Unit system by dividing 13 consolidated companies into 4 business field. |
| 2020年03月 |
Acquired shares of Daiichi Co., Ltd. (Sayama, Saitama) and made it a consolidated subsidiary. |
| 2020年10月 |
YAC Garter Co., Ltd. (surviving company) merged with Daiichi Co., Ltd. (disappearing company). |
| 2020年10月 |
Terminated business unit system. |
| 2021年04月 |
YAC Denko Co,.Ltd. (surviving company) and YAC Kokusai Dennetsu Co.,Ltd. (disappearing company) merged. |
| 2022年04月 |
Moved from the First Section of the Tokyo Stock Exchange to the Prime Market |
| 2022年10月 |
ワイエイシイマシナリー株式会社（存続会社）とワイエイシイ新潟精機株式会社（消滅会社）を合併 |
| 2022年10月 |
Y.A.C. Machinery Co., Ltd. (surviving company) and YAC Niigata Machinery Co., Ltd. (diappearing company) merged. |
| 2023年04月 |
YAC Denko Co.,Ltd. (surviving company) and Y.A.C. Technology Co.,Ltd.(disappearing company) merged. |
| 2023年04月 |
Acquired shares of JE International Corporation and GD tech Co., Ltd. and made them consolidated subsidiaries. |
| 2023年05月 |
Concluded an agreement on capital alliance with Linus Biotechnology Inc. |
| 2023年09月 |
Ohkura Electric Co., Ltd. acquires all shares of Hosyo-Sangyo Inc. and makes it a consolidated subsidiary. |
| 2024年04月 |
YAC BIO Inc. is established and becomes a wholly owned subsidiary. |
| 2025年01月 |
Partial acquisition of TT Holdings, Inc. shares, which owns 100% of the shares of Topcon Technohouse Corporation, to make it a consolidated subsidiary. |
| 2025年04月 |
Topcon Technohouse Corporation changed its name to TechnoOptis Co., Ltd. |
| 2025年07月 |
Acquired additional shares of TT Holdings, Inc., which owns 100% of the shares of TechnoOptis Co., Ltd. to make it a wholly owned subsidiary. |
| 2026年01月 |
TechnoOptis Co., Ltd. (surviving company) and TT Holdings, Inc.(disappearing company) merged. |
| 2026年03月 |
Acquisition of Sanwa Electric Instrument Co., Ltd. and Sanwa Tesmex Co., Ltd. as Subsidiaries. |
