In the period of the Northern and Southern Courts, many families of the Shinano-Ogasawara clan belonged to the Northern Court, but there were some people belonging to the Southern Court such as Jujiro OGASAWARA, the fourth son of Sadamune OGASAWARA, who is said to be the one who constructed Haba-jo Castle.
南北朝時代には信濃小笠原氏の一族の大多数は北朝に属したが、小笠原貞宗の四男で羽場城の築城者とも伝わる小笠原重次郎など、一部に南朝に属した者もいる。