Shikigami no Shiro (roughly translated as Castle of Spirits; known as Castle of Shikigami in the West) is a series of Bullet Hell Shoot Em Ups developed by Alfa System. The overarching plot involves a mysterious castle in the country of Alcaland, which has been the subject of many "missing persons" cases. A handful of psychic soldiers have converged on the location to conduct their own investigations of the incident, each for his/her own reasons. As of 2008, all three games have been released in the U.S. for the Play Station 2 (first two games) and Nintendo Wii (third).