I have two of his knives .... I picked up this one and later a smaller blade to partner it ....
This has a 10 inch blade and is called the Daruma ... it came with a convex hamaguri-ba grind and was very sharp .... my knives are all users and here are a few pic's of my taking it out to compare it with some Busse's I have .... the Bushwacker Mistress Limited Edition and a Basic 11 .... the BWM LE has a convex edge and sabre grind .... the Basic 11 has an asymetrical edge and flat grind ....
I put it through it's paces chopping and batoning wood .... comparing it with these knives ....
I added a thinner Bushwacker Mistress which came painted and which I stripped and fully convexed .... this model came flat ground and is thinner stock at .187 .... the reason I brought this one out was that I felt the hamaguri-ba grind on the Kiku knife was a bit thick behind the edge .... sort of more pear drop convex than a thinner appleseed shape which I find works best .... you can tell this with your eye and how the blade works if you use them enough .... so despite the lovely acid etch finish I decided to thin the grind down ....
I marked off the area I wanted to remove and using a belt sander and some good belts I did the job slowly and avoiding heat build up in the blade ....
Here is a picture of the finished result with the smaller Kozuka utility knife ....
Whilst I regret losing the etching .... it would have been eroded over time and use .... it now looks more of a "user" but more importantly for me it is now razor sharp and performs perhaps the best of my large 10 inch blades ...
It will shave arm hair so you don't feel them being cut .... and at a Rc hardness of Rc62 is well able to retain the edge for a long time ....
In comparison Infi at Rc 58 needs stropping more frequently to retain the edge but both don't dull much when used on chopping wood .... however used on game and butchering carcasses for the Deer Larder the Kiku Matsuda knife is noticeable for it's longer edge retention.
OU31 steel is why I bought these knives .... to try the steel out and to give me something of a higher Rc hardness for a large knife which I was interested in working with ...
Kiku Matsuda is perhaps the best living free hand grinder of blades .... he can create blades with complex hollow and convex and flat grinds all combined .... his skills as a grinder were acknowledged when after years of doing all the custom high end folders for William Henry he was asked to do a collaboration knife with SOG which won best of show at Blade 2007. His Hamaguru-ba grind though is perhaps more influenced by the fighting aspect of his designs and like some Japanese swords the thickness behind the shoulder of the edge must be there for potential blade on blade "contact" .... in any event the knife as it is now .... is much better at the tasks I use my knives for .... and those are primarily field and camp work and hunting and butchering game ....
The smaller Kozuka works fine as is .... the edge I touched up to the same level as the larger blade and for finer carving or working inside a carcass it excels .... again it is the edge holding quality I notice the most and it to is at a high Rc62 setting. This knife has a thin flat grind and very much is my preference for a knife from the off.