ridges on a blade (sword, knife, etc.)(shinogi)
The high, vertical line running between the blade and the mune on the side of the sword blade. This line is called “Shinogi-suji. The blade of a sword with shinogi-suji is thinner and lighter. This makes the blade sharper and easier to handle in battle.
This technique of making the blade thinner and lighter makes the blade sharper and easier to handle in battle. Originally, the focus was on “thrusting” attacks with a straight sword without Shinogi, but this changed to “stroking and cutting” attacks with a swinging sword, and the sharpness and lightness of the blade, as described above, came to be demanded. If the blade is made thin all over, it is more likely to break, but by leaving a thicker section with Shinogi, the blade can remain sturdy and resistant to breakage.
The term “sharpen Shinogi-” is derived from the fact that the two blades are so close to each other that their Shinogi-line touches each other, and the word “sharpen” is used to describe the fierce struggle between them.
