The Masahiro family of swordsmiths prospered for eleven generations from the early Edo period until the death of the eleventh in 1902. The first was working under the name Tadayoshi, but received the name Masahiro from Lord Nabeshima in 1626, together with a villa and a considerable income. He was invested as Kawachi no Kami in 1628, and died in 1665 at age fifty-nine. This sword is by the second generation, who has also left swords signed Musashi Daijo, Musashi no Kami, and from 1665 onwards, Kawachi no Kami. The cutting test inscription implies that the sword cut through an iron helmet.