Touhou Tenkuushou ~ Hidden Star in Four Seasons is the 16th game in the Touhou Project series. It was announced on the developer ZUN's blog on April 20, 2017. A playable demo was released on May 7, 2017, at Reitaisai 14, and the full version was released at Comiket 92 on August 11, 2017. The game was released on Steam worldwide on November 17, 2017, becoming the first game in the series to be available on the platform.