I bought a few days ago this small Japanese knife.
Model - Nagao Higonokami HKI-080BL. Blade lenght 80 mm.
I liked the design and quality 3-layer steel.
Then I looked a little information.
These knives have been established in the Meiji era.
While dismissed Samurai and the laws were tightened,
i.e. no one could have a knife with a fixed blade
or folding having a lock.
Therefore, the Japanese have come up with this knife
and used it everywhere.
The knife has a very simple construction - 3- or 1-layer blade,
one-piece steel/brass handle and steel axis/rivet.
If you use must be careful.
As say one worker who makes these knives - thin handle and
a lack lock in childhood children are taught to use
a knife carefully and correctly.
I think it is quite correct practice.
In the knife there is one drawback - the knife cuts into
its own handle and blunts.
I pasted a piece of skin in the handle for the blade not dulled.

here's a good video


I apologize for the quality of my photo

Interestingly, someone here still have some knife?