blade length51.8cm, curvature 0.9cm, thickness at the base 7mm, width 2.7cm
This is a wakizashi which is shortened from long blade. We think its original style was tachi blade from Kamakura period.
The steel is a large wood grain pattern, but the layer is not rough. The steel colour is not very bright except for the part from monouchi to kissaki. The part from monouchi to tip is very bright (or clear).
The hamon also is dim except for the part around monouchi to kissaki. The hamon around monouchi to kissaki is bright made of small particles. Hamon pattern is straight including steep ashi (saka-ashi), and some effects of large wood grain layer pattern. The hamon in kissaki is a straight and small round top, but includes sweeping pattern a little at the top.
This blade is freshly polished up by Mr. Rinzo Negishi who is one of the master polishers in the classical style. The polishing is very useful to study the blade.
By careful studying, we can guess the steel construction to Kobuse. The outer steel covers the area near the cutting edge all through the blade. And the border between the edge steel and the body steel makes some wavy appearance around the hamon.
This blade is not very weary considering the grooves and the hamon in kissaki. So the milder hamon in lower part of the blade may be original.
Tang
It shows a proper manner of the blade shortening work. (=> Manner of blade shortening)
It is difficult to find out the smith. Some friend attributes it to Aoe, and some does it to Nioh. We think the both are possible.