Gassan is the name of a mountain in Unshu. Around the mid-Kamakura period, there was a swordsmith who hailed from there, using only the name Gassan, and no first name. Gassan had started a school for his uncommon (but beautiful) making of the kantei points and hamons on his swords in Osaka, but the school and his tradition died out in the early Edo period. In 1836, Gassan Sadayoshi revived the school of Gassan sword making after his master's (Suishinshi Masahide) death in 1825. It is possible this katana is a tribute to either Gassan, from the Kamakura period or Sadayoshi himself.