Kamiizumi Castle

 was a Japanese castle located in the province of Kōzuke during the early Sengoku period of Japanese history. Throughout the course of the period, the castle was controlled by the father of the famous swordsman Kamiizumi Hidetsuna, whose name is unknown. It is known that Hidetsuna's father made sure that Hidetsuna was very well versed in the ways of "bujutsu" (martial arts), in which he thoroughly trained his son many times near his castle. Through his father's training, Hidetsuna soon on became a master of the spear and sword.