| 1937 |
Established Okutama Electric Railway Co., Ltd. |
| 1944 |
Renamed as Okutama Kogyo Co., Ltd. |
| 1946 |
Started mining and selling limestone |
| 1961 |
Established Okutama Kako Co., Ltd. to manufacture quick lime |
| 1961 |
Started manufacturing and selling quick lime |
| 1965 |
Started manufacturing and selling slaked lime |
| 1967 |
Established Mizuho Kenzai Kogyo Co., Ltd. to manufacture crushed stone |
| 1975 |
Started manufacturing PCC(Tama Pearl) |
| 1995 |
Started manufacturing and selling Tamakalk
(slaked lime for flue gas treatment) |
| 2002 |
Established Niigata PCC Co., Ltd. |
| 2003 |
Established Yokohama Kairyodo Center Co., Ltd. to carry out the PFI business for the Sewage Works Bureau of City of Yokohama |
| 2007 |
Established Sanyo Taiheiyo Lime Co., Ltd. |
| Campany Name |
Type of Business |
| Okutama Kensetsu Kogyo Co., Ltd. |
Engineering work & construction |
| Mizuho Unyu Co., Ltd. |
Freight Forwarding |
| Niigata PCC Co., Ltd. |
Manufacture & sale of Tama Pearl |
| Yokohama Kairyodo Center Co., Ltd. |
Manufacture & sale of stabilized soil |
| Advanced Co., Ltd. |
Engineering work & construction |
| Fukuyama Mizuho Unyu Co., Ltd. |
Freight Forwarding |
| Sanyo Taiheiyo Lime Co., Ltd. |
Manufacture & sale of quick lime |
