In Naruto, ninjas wear a forehead after becoming a ninja, and the forehead becomes a symbol of the ninja, and the pattern on each forehead is different, which means that they come from different ninja villages, but in the anime, the members of the Xiao Organization are all rebellious ninjas, why do they wear a forehead after leaving the village?
The members of the Xiao Organization are rebel ninjas from all over the world, and after joining the Xiao Organization, the first thing they have to do is to draw a knife on their forehead, and the first person to do so is Nagato, one of the founders of the Xiao Organization, Nagato after the negotiation with Yamaji Hanzo failed, Yahiko sacrificed to save Konan, and after defeating the enemy, Nagato slashed a knife on the forehead.
Later members of the Xiao Organization will also do such things like Nagato, Uchiha Ferret, Deidara, and Hidan all scratched a knife on their foreheads, but for some people, it is just a small forehead, how can a knife be done, but in the world of Naruto, the forehead is still very important for ninjas.
First of all, the forehead is a sign that a person officially becomes a ninja, in the first episode of the anime, we can see Naruto's desire for the forehead, only by wearing this forehead can you truly become a ninja, and the pattern on the forehead can also make people quickly understand which village they come from, in the ninja world, it is also a kind of ninja proof.
Later, during the battle between Naruto and Sasuke on the rooftop, Naruto also strongly asked Sasuke to wear a forehead, Sasuke did not think so, thinking that the forehead was just a simple protective gear, but for Naruto, only both sides took the forehead, this is an equal battle, and later the two people first in the valley of the end of the battle, Sasuke did wear a fair battle with Naruto.
Therefore, for ninjas, the forehead is also a kind of faith, after becoming a renegade ninja, drawing a knife on his forehead means that he will break with the faith he once had, and at the same time he will break with the ninja world, and in the anime, Uchiha mustela is very heavy when he draws this knife, because he still has some worries in his heart.
Not only that, but doing so also means that these renegades have to say goodbye to their former selves, and after becoming rebels, they will not protect the village, nor are they any village ninjas, they are just walking in this world, but they are contrary to this world, and they take the initiative to do it, which also shows that they have abandoned this world, not abandoned by the world.
However, the most important point is that in order to facilitate identification, since it is a rebel, it must have its own exclusive sign of renegade, and renegade will not write these two words on the face, so Kishimoto Kishi used the forehead to show the identity of the rebel, and drawing a knife on the forehead is undoubtedly the best approach, and it will not make the character particularly awkward, and can show the identity.
And after a knife was drawn on the forehead, the forehead seemed to be a little more handsome than before, but no matter what they did to the forehead, they were once the ninjas of this ninja village, and they had fought for this village, and it was estimated that this was what Kishimoto Sensei wanted to express, no matter what you do now, you were once the best ninja in this ninja village.
In your opinion, why should the rebellious protector slash a knife?