A reasonably developed ninja world

There are many different schools of swordsmanship in Konoha. .There is the Hatake style who is invincible, and there is the Gekko family's clone arc that kills them.

The Maruboshi family are masters of illusions that use visual principles. Whenever someone from the Maruboshi family used a special move, the enemy would see a sword swinging in the wind like a willow leaf, slowly and gracefully. In fact, it is almost to the extreme.

The human visual resolution speed is about 1/24. This principle applies to both movies and television. Every second, 24 frames of images are played, so that the images on the screen seem to be coherent.

When a sword stays in a person's line of sight for less than 1/24 second, it means that the human eye cannot capture the sword. This is the true shadowless sword in swordsmanship. It is a true shadowless sword that is different from transparent swords, hidden swords, and assassination swords.

Of course, the swordsmanship of the Maruboshi family cannot reach this level. What kind of illusion is needed to achieve this kind of speed? They took another path, which was rhythm.

Since it is difficult to increase the speed of the entire person, it is better to increase the speed of the sword to create phantoms in a small area of ​​​​the body. It's like holding one end of a steel tape measure with our fingers and flicking the other end of the ruler with the other hand. The steel tape measure swings back and forth, creating a phantom.

The Maruboshi family uses high-speed flicking of the wrist to swing the sword back and forth. This creates the feeling that the sword is swinging slowly like a willow leaf, but in fact the sword is swinging back and forth at high speed.

Then use the big arm to drive the wrist and sword to make large-scale, regular movements.

When the image seen by the human eye disappears, the human eye can still retain its image for about 01-04 seconds. This principle is called visual residue. China's Song Dynasty used this principle to invent the revolving lantern.

In this way, countless swords swinging like willow leaves appear in the enemy's eyes.

Such a move, the rhythm of the sword and the rhythm of the arm, can be described as harsh. Therefore, when using this move, the Maruboshi family cannot move and must keep a certain distance from the enemy. If you can't move, how can you attack?

That is the third principle. When the human eye stares at regularly changing objects, it will cause visual fatigue in a short period of time. Just like highways are never straight. A straight highway with regularly changing street lights on both sides can cause people to lose all their attention without even realizing it, leading to a car accident.

Those who are weak-willed and keep staring at the Maruboshi family's special moves will lose their concentration and be unable to move as if they were under an illusion. Even those with strong willpower may lose consciousness for a moment. This is the time to take the enemy's life.

The Maruboshi family's swordsmanship has strict requirements on wrists, arms, and rhythm. Kosuke is young and the illusions he creates are difficult to have an effect on ninjas. But he understands the basic principles, and he has definitely gone through hard training.

Then why does Nagata understand the Maruboshi Kosuke family?