According to one of the Japanese classics, "Taiheiki," Morinaga was confined in prison with mud walls in Toko-ji Temple （the prison with mud walls were restored and still exists on the site of Kamakura palace).
古典『太平記』では、東光寺の土で壁を固めた牢に閉じ込められたことになっている（土牢は鎌倉宮敷地内に復元されたものが現存）。