The work of Muramasa was considered inauspicious to the Tokugawa shogun's family, since swords by the smith were said to have been used several times in incidents during which members of the family were injured or killed.
Although it has been slightly re-shaped, the tang is of the classic form used by Muramasa known as tanago-bara [bitterling fish belly]. The earliest recorded blade by Muramasa is dated to 1501, and there are dated blades believed to be by the second and third generations dating from between the 1530s to the 1570s. There are later swords signed with the name Muramasa, but their relationship is not clear. This sword is possibly by the third generation. The blade has a kirkomi kizu [sword cut mark] on the omote just below the yokote.