Sansei Co., Ltd. engages in the design, manufacture, sale, and installation of gondolas and stages for window cleaning. It operates through the following segments: Gondola and Stage, Marine-Related, and Others. The Gondola and Stage segment deals with the design, manufacture, sale, installation, maintenance and repair of gondola and stage set for window cleaning use. The Marine-Related segment handles the ship repair; production of fishing reefs and floating light beacons; and lodging business for seafarers. The Others segment includes the manufacture and sale of industrial machines and real estate management services. It also offers the rental of temporary gondolas; and manufacture and sale of industrial machines. The company was founded on December 20, 1956 and is headquartered in Osaka, Japan.