Kenkon ("Spirit of the Sword) was produced until 2000. The steel is Blue
Super Steel made by VAR(Vacuum Arc Resmelting) method. It is not a special
edition or anything, but since it has been featured in a very famous tool
photo book (infamous for raising the price of the tools that it features)
they are very rare and expensive. Definitely a super collector's item.
The box was signed by the temple master of Yakushi temple. It has the branding of Yakushi temple as well.
The blade was forged in Shouwa 62 (1987), Nov.