The registration document attributes the blade to Hiroyasu, and states that it was in the old collection of Sakamoto Itaru. Old documents tell that Hiroyasu was a pupil of the first Samonji who had studied under Masamune. Other contemporary smiths in Chikuzen include Yasuyuki, Yoshisada, Yoshihiro, Yukihiro, and Yasuyoshi, and some of these signatures are found on later work of the Muromachi period. The swords of the school are distinctive, with a fine hada rich in jinie, often mixed with a larger flowing hada, and a bright hamon of suguha with complex variations of midare and gunome. The boshi is typically rather pointed with straight angled return, often with hakikake. Since the tachi of the period are invariably cut-down, the signatures are lost, and it is difficult to distinguish between the different smiths.