Review: Hatsukokoro Komorebi (A Better Yoshikane?)

[tostadas]

At one point, I was looking for a Yoshikane, but with some changes. I liked the grind that effortlessly falls through everything, the Sanjo style taper, and the forward balance. But if they could also make one that was taller and not so flat… wouldn’t that be perfect? Well, I think I’ve found just that in the Hatsukokoro Koromebi.

Intro
I got this knife mainly because of the advertised specs: approx 240x55, midweight, nice steel, cool looking finish. It’s available from a number of retailers, the one I have in particular with a nice handle from K&S. After testing it out for a while, there are a lot of things I like about this, and some things I think can be improved.

Specs
Blue#2 core w/ soft iron cladding
K&S Teak/Horn handle

Blade Length: 245mm
Height at Heel: 56mm
Weight: 218g*
Balance from Heel: 35mm* forward
*With 210mm “thick gyuto” teak handle

Spine Thickness

Handle​	Heel​	Midpoint​	1cm from tip​
4.1mm​	3.7mm​	2.3mm​	0.6mm​

Thickness Behind the Edge at Midpoint

@1mm​	@5mm​	@10mm​	@20mm​
0.1mm​	0.5mm​	0.8mm​	1.6mm​

Geometry/Performance
The maker is not disclosed, but if you handed me this knife to use and provided no other info, I’d say it was Yoshikane. There’s a gradual taper from a respectable 4.1mm out of the handle down to a stupidly thin 0.6mm toward the tip. The edge profile features roughly 2.5inch flat spot at the heel that transitions with a gentle curve to a fairly standard tip height of approx 19mm. There is plenty of flat spot for push cutting, but not as excessive as on the Yoshi.

The grind seems strikingly similar to Yoshikane. High, consistent, even grind on both sides that’s near flat, or ever so slightly concave with a defined shinogi line. Behind the edge thickness is nail-flexing thin. It falls through everything with little to no effort. The blade has a polished, brushed finish which is ease to care for. There is a quick and dirty kasumi finish that is decent. Feels better than a sandblast finish and doesn’t cause unnecessary drag, though I’d prefer it to be a bit smoother.

Fit, Finish & Aesthetics
The spine and choil are eased slightly. There are no square edges, but I think it could use some additional refinement, especially right at the choil curve area. The kanji is engraved (not screened on), but doesn’t look like it’s done by hand with a chisel. More like a computer controlled engraving I’ve seen somewhere on a nice Japanese knife, but can’t put my finger on which. The finish on the blade feels refined like on many Sakai knives. I mentioned the kasumi finish earlier which is decent but not amazing. The handle I have installed is teak/horn from K&S. I prefer a thicker grip, so I got the “thick gyuto” version in a shorter 210mm size to keep the balance more forward. K&S always has the cleanest installs with minimal gap between the tang and handle, so I highly recommend getting one. The handle is shaped consistently on all sides, but there’s a noticeable lip between the wood and the horn on mine. I plan on refinishing the handle anyways, maybe also torching the teak, so having that lip is no big deal for me.

Closing Thoughts
This knife is an amazing value for the price. It really feels to me like an improved version of a Yoshikane in every way. I’m going to make some additional F&F improvements to it and see if this can earn a permanent spot in my rotation.

If anyone else has tried one of these, I’m interested to hear your thoughts as well.

 

[madmotts]

Nice review. I’ve been waiting to hear about these since they showed up on KnS. I have a couple of taller 240s- matsubara and manaka. Sounds like I need another.

 

[timebard]

Nice writeup, sounds like a winner! How is the reactivity of the iron cladding?

 

[MattPike4President]

Sweet review! Knives that cut like Yoshi's but taller and curvier are more or less exactly what I'm looking for in a primary work knife. I'll have to check back in if I ever decide to get some fully reactive blades into my kit.

The finish on the blade feels refined like on many Sakai knives. I mentioned the kasumi finish earlier which is decent but not amazing.

The KnS description for this knife really emphasizes that it was finished on Jnats. They compare it to Shigefusa who I'm not super familiar with but seems to have quite a reputation around here. Seems like your takeaway on finish was 'good but not great', which doesn't quite live up to that marketing.

Or perhaps I'm misinterpreting the appeal of finishing on Jnats. Is it about the aesthetic finish or having fewer low spots and overgrinds due to not finishing on a grinding wheel?

 

[tostadas]

Nice writeup, sounds like a winner! How is the reactivity of the iron cladding?

Cladding feels like a typical iron cladding. Nothing out of the ordinary. I suspect that reactivity has a lot to do with the finish on the blade. Fine brushed finishes, as in this case above the shinogi line, are one of the least reactive in my experience. The blade road with the kasumi finish is rougher, so it takes patina more readily. I tested the stock finish on a lot of onions and tomatoes, and never did I feel like I had to rush to rinse it off for fear of bright orange rust developing.

The KnS description for this knife really emphasizes that it was finished on Jnats. They compare it to Shigefusa who I'm not super familiar with but seems to have quite a reputation around here. Seems like your takeaway on finish was 'good but not great', which doesn't quite live up to that marketing.

Or perhaps I'm misinterpreting the appeal of finishing on Jnats. Is it about the aesthetic finish or having fewer low spots and overgrinds due to not finishing on a grinding wheel?

The finish is definitely a step above the sandblasted finish you will find on many Japanese knives. I assume that this knife is ground like any other, on a large wheel of some sort. Then following that, it has a brushed finish running from heel to tip. And on top of that brushed finish, there is a natural stone rubbed finish along the blade road. It's clean, doesnt cause any noticable drag, but it's not as consistent (in terms of scratch pattern) as I personally would like. But at this price point, I think it's very good.

 

[superworrier]

So the page says it is indeed made in Sakai. The cladding is Y Tanaka esque but idk if it’s inljne with the price. There’s a dammy version now too

 

[tostadas]

So the page says it is indeed made in Sakai. The cladding is Y Tanaka esque but idk if it’s inljne with the price. There’s a dammy version now too

It's possible. However I couldn't say one way or the other for this knife. If it had some sort of less refined finish like a KU or nashiji, then you might have some clues to deduce the smith. But with this one that's had any remnants from forging polished off, I have no idea.

 

[big D]

Specs
Blue#2 core w/ soft iron cladding
K&S Teak/Horn handle

Blade Length: 245mm
Height at Heel: 56mm
Weight: 218g*
Balance from Heel: 35mm* forward
*With 210mm “thick gyuto” teak handle

Spine Thickness

Handle	Heel	Midpoint	1cm from tip
4.1mm	3.7mm	2.3mm	0.6mm

Thickness Behind the Edge at Midpoint

@1mm	@5mm	@10mm	@20mm
0.1mm	0.5mm	0.8mm	1.6mm

Blue #1 Dammy
54.5mm 244g
Spine -267
edge - 246

Spine
handle - 4.97 Heel 4.05 Midpoint 134mm from handle - 1.83 45mm from tip -1.65 10mm from tip -0.62
134 from the handle
I Tried
@1mm -.01 @5mm .48 @10mm - .78 @20mm - 1.4

I purchased this after your write up which sounded good. I had been looking at your version, but really wanted to give Blue#1 a spin. I also wanted a true 240mm or a bit longer. As such I ended up with the dammy to get the Blue#1. The height did give me pause for two reasons. One is upon occasion (I wear Xtra large gloves and typically can find a couple pair which aren't going on or to tight) I like to slip the blade between my finger, and thumb and make a few cuts before turning the blade and cutting normally, IE: a big handle full of spinach. I am able to do this fairly comfortably since the spine heads down and the edge heads upward making the height substantially less nearer the tip. This also makes passing through things (onions etc.) quite nice along with being thin. Now in the Blue#2 with the thicker spine this may not show up as badly, but in mine with the height it is as I feared. All that I have cut so far is are a couple of onions and a carrot . These all wish to stick to the blade. This may still very well work out for its intended purpose, big bowls of potato salad, Turning big heads of cabbage into slaw etc etc

 

[madmotts]

i picked up a b1 damascus 210 (217mm) and the grind kind of looks like the above picture, but it's not anywhere like yoshikane thin behind the edge. I think the b2 version is a different animal, probably more of what i'm looking for. It almost gets stuck on the apple test, pretty sticky and uber reactive. With that being said it's a really nice knife, it's got some weight, thick as hell coming out of the handle 5.5mm (2mm midpt) and height around 53+. It's got a gorgeous damascus wavy pattern on it that's more wave-like than swirls.

 

[tostadas]

Update:
Spent the past few weeks making modifications to address the things that bothered me initially with the Komorebi.

• Reprofiled the heel just barely to change the super flat spot to have a touch of curvature. Smoothed out the cutting by fixing the hard stop ("thud") near the back of the knife, similar to what I experience in the Yoshikane.
• Sanded down the handle flush with the ferrule and smoothed out some sharp spots. Torched the handle, then polished and waxed the horn ferrule.
• Fully rounded the spine and choil.
• Removed the stock finish. Full kasumi and etch. Some interesting details even came out in the core after polishing.

The result makes me smile. Tested it today and it performs exactly like I was hoping.

 

[Jbeercow]

How did you go about reprofiling the heel? I've been wanting to do that to my Yoshikanes.

 

[tostadas]

How did you go about reprofiling the heel? I've been wanting to do that to my Yoshikanes.

Here's a sketch of the basic idea, but greatly exaggerated to show it visually.

Assume the blue line is the flat part. You can identify the front and back of the flat by rocking the knife and feeling where it stops.

1. I hold the flat part on a 220 grit sandpaper and the goal is to grind just enough from the front, so that it is not dead flat. I proceded to push the knife laterally while rocking the knife approximately where I have the orange line drawn. So again, the idea is to remove the bare minimum amount of steel, so the amount of pressure is as close to zero as possible. I'm pretty much holding the knife up with 2 hands and just kissing the sandpaper.
2. Do the same thing at the very heel if needed. I think this depends on the angle that the knife sits when flat relative to the handle, and what that angle actually looks like for your particular cutting motion. So this step may not be necessary.
3. Rock the knife and see if the flat spot is better. If not, continue at the front of the new flat spot, similar to step 1. Repeat as necessary.
4. When you're done, resharpen. With the minimal amount of steel I removed, thinning is not necessary.

 

[madmotts]

So messing around with vinegar and coffee for my first etch. Probably could have done on a different knife. Man it’s a lot of work to even get it here…

 

[tostadas]

Update #2:
The new finish seems to help with the patina. The stock finish got brown really fast. Here's where we're at now after about a week of home use.

 

[madmotts]

I picked up a 240 dammy last month from Tosho and it's different than the 210. Much thinner BTE. I see u @tostadas- Since you have both B1 and B2, think they're the same smith? and who do we think it is? let's keep this thread going.

 

[jedy617]

Love my B2, it's super thin

 

[tostadas]

I picked up a 240 dammy last month from Tosho and it's different than the 210. Much thinner BTE. I see u @tostadas- Since you have both B1 and B2, think they're the same smith? and who do we think it is? let's keep this thread going.

I can't tell who the smith is, but my bet is that the sharpener is different because the grinds and profiles are so different. My b2 was flat profile and also had a pretty high, flat, wide bevel grind. In contrast the b1 has gently curved profile with a right-biased, insanely thin convex grind. Fit and finish of the stock spine/choil is also much better on the b1.

 

[EdgeFundManager]

Does anyone know what the kanji means? It looks identical to the kanji on my Yoshikane.

 

[tostadas]

Does anyone know what the kanji means? It looks identical to the kanji on my Yoshikane. View attachment 207918

It's the hatsukokoro brand kanji