Hiroshi Tominaga

OSJB Holdings Corp. operates as a holding company that engages in the planning and management of its group companies those are engaged in the design, fabrication, installation, and construction of bridges, steel frames, and steel structures. It operates through the following segments: Construction, Steel Structure and Others. The Construction segment engages in the construction, manufacture and sale of pre-stressed concrete; construction of pneumatic caisson and repair works; design and construction of anti-seismic reinforcement; and sale of construction materials. The Steel Structure segment handles the design, production, and installation of steel structures such as bridges and others. The Others segment engages in the generation and sale of power through solar power generation. The company was founded by Katsujiro Iwai on July 7, 1919 and is headquartered in Tokyo, Japan.