Forged W2 steel blade 13″ nagasa. Differentially heat treated using water during yaki-ire to create a hamon reminiscent of an enraged ocean to match the crab claw menuki and engraved crab in the fuchi and kashira. The tsuba is made from copper that was melted and poured into boiling water -yuwake-. Copper made in this way takes on different coloration during the patina process using the niage technique and more vivid browns and reds can be coaxed out of the metal creating a slight contrast to the lighter brown and orange coloration of the seppa, fuchi and kashira. The saya is made of lacquered poplar with copper rim and horn kurikata.