Yamamura Masahiro of the Sue-Soshu school (cf. Lot 431) was summoned to Odawara sometime around the 1530's by Hojo Ujitsuna, and was re-named Tsunahiro having been granted the use of the character Tsuna from the lord's name. Two generations followed, of whom the third named So'uemon no jo is famously said to have been commissioned by the lord of Tsugaru to make three hundred daisho blades. He returned to his home province in 1606, and died in 1638 aged ninety one. All three generations made swords with midare-ba or hitatsura like this blade.