| 1964 (Showa 39) |
Noboru Wataru founded the sole proprietorship Yamaichi Sangyo for the purpose of renting machinery and tools. Providing double rental (wholesale rental) services for temporary construction equipment and materials to industry peers. 
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|---|---|
| 1971 (Showa 46) | Established Yamaichi Temporary Construction Co., Ltd. |
| 1974 (Showa 49) | Separated and established the wooden scaffolding division as Yamaichi Ringyo Co., Ltd. |
| 1978 (Showa 53) | Yamaichi Sangyo Co., Ltd. was established for the purpose of selling used construction materials and equipment. |
| 1986 (Showa 61) | Separated the housing division and established Yamaichi Container Co., Ltd. |
| 1994 (Heisei 6) |
In response to customer needs, Yamaichi Scaffolding Co., Ltd. merged three group companies to consolidate management and improve efficiency, marking a fresh start. Noboru Watanabe assumes the role of Representative Director and Chairman, while Kenzo Watanabe assumes the role of Representative Director and President. 
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| 1996(Heisei 8) | Launched "Renewal 21," a new business system utilizing LAN implementation. |
| 1997 (Heisei 9) | Changed the company name to Act-One Yamaichi Co., Ltd. |
| 2000(Heisei 12) | Nagoya Sales Office and same machinery center established. |
| 2001 (Heisei 13) | Migrated the "Rinyu 21" business system to the "Acts" business system. |
| 2002(Heisei 14) | Kawasaki Sales Office and Kawasaki Machinery Center established. |
| 2004 (Heisei 16) |
Opened Urayasu Sales Office and the Urayasu Machinery Center. Opened Toda Sales Office and the Toda Machinery Center. Discontinued the housing business. |
| 2005 (Heisei 17) | Relocated the head office building from Higashiosaka City to Nishi-ku, Osaka City. |
| 2006(Heisei 18) | Kobe Sales Office and Kobe Machinery Center Established |
| 2007 (Heisei 19) |
Kawasaki Office and Material Center relocated. Tama Office and Material Center established. Osaka Office and Material Center established. Discontinued general temporary scaffolding material business and single-tube scaffolding business. |
| 2009 (Heisei 21) |
Toda Sales Office and the same machinery center relocated. Opened Hirakata Machinery Center. |
| 2011 (Heisei 23) |
Relocated the head office building from Nishi-ku, Osaka to Kita-ku, Osaka. Relocated the Urayasu Office and the Machinery Material Center. |
| 2012 (Heisei 24) |
Migrated from the "Acts" business system to the new "Links" business system. Opened the Sendai Sales Office and the Sendai Machinery Center. |
| 2013(Heisei 25) |
To prepare for future business expansion with potential partnerships in mind and to act as the command center for the group, Act-One Holdings Co., Ltd. was established as a holding company. Through a share transfer, our company has become a wholly owned subsidiary of Act-One Holdings Co., Ltd. |
| 2014 (Heisei 26) |
Celebrating our 50th anniversary. Renamed Tama Office to Tama Equipment Center. |
| 2015(Heisei 27) | Relocated the Tamamo Material Center and renamed it to the Sagamihara Material Center. |
| 2016 (Heisei 28) |
Relocated the Kobe Sales Office and its material center to Nada-ku, Kobe City. Relocated the Osaka Sales Office and its material center to Taisho-ku, Osaka City. |
| 2017 (Heisei 29) |
To achieve further growth, we merged with Act-One Holdings Co., Ltd. and CCH6B Co., Ltd. to form the newly reborn Act-One Yamaichi Co., Ltd. Opened the Hiroshima Sales Office and the Hiroshima Equipment Center. Renamed the Osaka Sales Office to the Kansai Sales Office. Converted the Kobe Sales Office into the Kobe Equipment Center. |
| 2018(Heisei 30) |
Opened the Utsunomiya Equipment Center. Opened the Morioka Equipment Center. |
| 2019 (Reiwa 1) |
Opened Kanazawa Materials Center. Opened Kakegawa Materials Center. Opened Fukuoka Sales Office and Materials Center. |
| 2020 (Reiwa 2) |
Established the "Metropolitan Area Business Division" in Chuo-ku, Tokyo. Centralized order-related operations for the Kanto region into the Metropolitan Area Business Division. Converted Toda Sales Office into the Toda Equipment Center. Converted Urayasu Sales Office into the Urayasu Equipment Center. Converted Kawasaki Sales Office into the Kawasaki Equipment Center. Established the Iwaki Equipment Center. |
| 2021 (Reiwa 3) | Sapporo Sales Office and same-material center established. |
| 2022(Reiwa 4) | Kenzo Watanabe has stepped down as Representative Director and President, and Koji Yamada has been appointed as Representative Director and President. |
| 2023(Reiwa 5) |
Opened Kumamoto Equipment Center. Opened Kishiwada Maintenance Center. |
| 2024 (Reiwa 6) |
Celebrating our 60th anniversary. The Tokyo Metropolitan Area Business Section has been relocated to Chuo-ku, Tokyo, and renamed the Tokyo Office. |
| 2025 (Reiwa 7) |
Relocated the Toda Equipment Center. Established the Kanto Maintenance Center. Opened a resident representative office in Indonesia. |
