Penta-Ocean Construction Co., Ltd. engages in the provision of building, civil engineering, and environmental construction services around coastal areas. It operates through the following business segments: Domestic Civil Engineering, Domestic Architectural Construction, Overseas, Domestic Real Estate Development, and Other. The Domestic Civil Engineering segment offers civil engineering services across Japan. The Domestic Architectural Construction segment deals with local construction. The Overseas segment involves with civil engineering and construction work outside Japan. The Domestic Real Estate Development segment deals with real estate selling and leasing. The Other segment includes shipbuilding businesses, office equipment leasing, insurance agency business, and environment-related consulting business. The company was founded by Jinjiro Mizuno in April 1896 and is headquartered in Tokyo, Japan.