The STS Kaisei (海星), meaning “Sea Star” in the Japanese language, is a steel-hulled brigantine designed by Polish naval architect Ryszard Langer. It was built as Schooner in Elbląg, Poland in 1987. After re-rigging it is now a two-masted vessel, square rigged on the foremast, with fore-and-aft sails on the mainmast.