| Oct.1926 | Maruo Seifun Goshi Company founded in Nishioka Uozumi-mura, Akashigun, Hyogo Pref., and commenced production and sales of extender pigments for paints. |
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| Jan.1928 | Maruo Seifun Goshi Company merged with Harima Seifun Goshi Company and Akashi Seifun Co., Ltd. placed under their management. |
| Mar.1931 | Commenced production of light calcium carbonates. Kobe Branch Office established. |
| Sep.1932 | Tokyo Branch Office established. |
| Jun.1934 | Osaka Branch Office established. Commenced production of ground calcium carbonates. |
| Dec.1939 | Maruo Shoji Co., Ltd. founded in Kobayashi-cho, Taisho-ku, Osaka City. Sales Department reconstituted as a separate organization. |
| Aug.1944 | Tokyo Sales Office of Maruo Shoji Co., Ltd. reconstituted as a separate organization and Nitto Hakua Co., Ltd. founded. |
| Nov.1948 | Maruo Seifun Co., Ltd. established with main office located in Awaji-cho, Higashi-ku, Osaka City. |
| Feb.1949 | Commenced production of colloidal calcium carbonates. |
| Aug.1949 | Maruo Seifun Co., Ltd. merged with Maruo Seifun Goshi Company and main office transferred to Nishioka, Uozumi-cho, Akashi City. |
| Jul.1950 | Merged with Akashi Seifun Co., Ltd. |
| Apr.1953 | Merged with Maruo Shoji Co., Ltd. and reorganized as Osaka Sales Office. |
| Mar.1957 | Tsuchiyama plant completed and commenced production of colloidal and light calcium carbonates. |
| Dec.1959 | Toyo Hakudo Co., Ltd. established. |
| Mar.1961 | Nagoya Office established. |
| Aug.1963 | Company name changed to Maruo Calcium Co., Ltd. |
| Jan.1964 | Tsuchiura Plant completed and commenced production of colloidal and light calcium carbonates. Listed on the second section of the Osaka Stock Exchange, Inc. |
| May.1965 | Merged with Nitto Calcium Co., Ltd. and reorganized as Tokyo Sales Office. |
| Apr.1979 | Kyushu Calcium Co., Ltd. established. |
| Oct.1983 | Central Research Institute established. |
| Jun.1989 | Maruo Osaka Building completed in Fukushima-ku, Osaka City. Osaka Sales Office relocated to new building. |
| Mar.2001 | Order Receipt Center opened. |
| Sep.2003 | Maruo (Shanghai) Trading Co., Ltd. established. |
| Sep.2007 | Dongguan Liwan Nanotech Co., Ltd. established. |
| Jul.2013 | Listed on the second section of the Tokyo Stock Exchange, Inc. |
| Mar.2017 | Main office building completed. |