Among all the elements that have caught the attention and the curiosity of keen eye viewers of Demon Slayer: Kimetsu no Yaiba, there is one that no one can explain its changes and development: Tanjiro’s scar. This scar is the most defining physical trait of the main character. It appears to have the ability to change, as seen in anime and manga. The viewers’ curiosity about this scar is as significant as the curiosity surrounding Tanjiro’s Hanafuda Earrings and his Black Nichirin Blade. But the main question is, “why did Tanjiro’s scar change?”.
The truth is, the mark on Tanjiro’s face started as a scar he obtained by saving one of his younger siblings from getting burned by a boiling kettle. However, it developed to be the “Demon Slayer Mark,” a tattoo-like birthmark directly associated with the users of the Sun Breathing Technique.
The mark that started as a scar on the top right of Tanjiro’s head changed in episode 4 after the fight with the Hand Demon. Some viewers thought Tanjiro’s scar changed after being smashed into a tree by the mentioned demon, sort of like the scar getting worse. But most viewers were not so sure about this theory as the changes do not make any sense either visually or logically. Keep reading if you want to know all the explanations to fully understand the logic behind the changes.
SPOILER ALERT: there might be information about future events that have not taken place in the anime or movie, so keep reading at your own risk.
Since his first appearance on episode one, we saw a scar on Tanjiro’s forehead, which remains intact until he goes to attempt the Final Selection. This entrance exam needs to be successfully completed to be a part of the Demon Slayer Corps.
Tanjiro got the scar while saving his brother. As a kid, Tanjiro, who already had his heroic traits, saved his younger brother from a falling boiling kettle, resulting in a scar on the right top of his head.
However, it is shown that his father, Tanjuro, also had the same mark as his son. This latter fact led us to theorize that Tanjiro did not get the scar by saving his little brother, but by inheritance from his father, which makes sense after knowing about the Demon Slayer Mark and the birthmark of the Sun Breathing Technique users.
The first change came during his fight with the Hand Demon at the Final Selection. This demon had a long, bloody, and cruel story with Urokodaki Sakonji’s students; none of the 13 disciples survived. Of course, the Hand Demon had the same plan for Tanjiro, especially after knowing he was a student of Urokodaki. Luckily Tanjiro managed to defeat this demon and set the souls of the past students free, but not before getting smashed into a tree, resulting in a bleed on his head, over his scar.
Next time we see the scar is at the beginning of episode 6. After this point, we will never see the scar as it used to be, a patch of healed skin. Tanjiro’s scar changed to the Demon Slayer Mark from this episode, a deep red mark that resembles a crude flame mark.
This fight was one of the best fights within the Demon Slayer story, and it even broke the internet. The fight started on episode 19, and it was the most challenging fight for Tanjiro, who managed to make the mark evolve and grow. At first, the mark was just at the top right of his head, but after the fight, the mark got more prominent, covering a bigger part of his head.
With the development of the story, we have seen different stages of the mark, and there is no doubt all of them are a form of the Demon Slayer Mark, even the first stage that was presumed as a burnt scar.
The evolution of Tanjiro’s scar, or mark, represents his growth, and it might indicate that his body is becoming more adapted to fighting, with his abilities getting increased with every change. The mark has four primary forms that can be seen throughout the story.
- A patch of healed kin.
- The first transformation after fighting the Hand Demon.
- The mark’s growth after the fight with Rui.
- The awakening of Tanjiro’s Demon Slayer Mark happened the first time he fought the Upper Moon 6, Gyutaro, and when he fought against Hantengu.
The Demon Slayer Mark is a booster of physical abilities up to the point that enables the ones who possess this mark to fight on par with the Twelve Kizuki. The mark also provides a hyper perception (Transparent World) and turns their Nichirin Blades to a crimson color, interfering with a demon’s regeneration ability. This Mark is strongly associated with the users of the Sun Breathing Technique.
This mark can resonate. During the Sengoku Era, multiple Demon Slayers had access to the Demon Slayer Mark; this also happened when the Hashiras, who have no direct association with the Sun Breathing Technique, managed to awaken their Demon Slayer Mark.
The original mark is considered a catalyst and can spread to other Demon Slayers, but they have to meet the criteria through resonance.
This ability marked Muzan Kibutsuji and the Twelve Kizuki’s fate. The Hashiras were able to resonate with Tanjiro’s marks and accessed skills, rivaling those of the Twelve Kizuki.
From the Sengoku Era, one user of the Demon Slayer Mark was Yoriichi Tsugikuni, the first Sun Breathing Technique user, and some swordsmen who belonged to the Demon Slayer Corps.
It also has been implied that Tanjuro Kamado, Tanjiro’s father, had the mark. However, his Demon Slayer Mark did not evolve nor awaken.
According to the main storyline, the characters that could awaken the mark were Tanjiro Kamado and the Hashiras like Giyu Tomioka, Gyomei Himejima, Mitsuri Kanroji, Sanemi Shinazugawa, Obanai Iguro, and Muichiro Tokito.
After enhancing his physical and mental capabilities, Tanjiro managed to awaken his Demon Slayer Mark. As the story evolves, it gets to the final form, which only changes when activated.
The first time Tanjiro awakened the Demon Slayer Mark was while fighting the Upper Moon 6 demon Gyutaru when Tanjiro realized he would need much more power to defeat him. When Tanjiro managed to trap Gyutaru under him, the scar started to change, which was also noticed by Gyutaru.
Tanjiro’s mark changes into two marks resembling blazing flames, both on the left side of his head, One in the same position of the original mark and ending above his eye; the other one is smaller and starts at the temple and ends under the side of his eye.
Tanjiro’s scar (which appears to be unchanged from when he battled Rui) is completely redesigned. We witness his scar evolve from a simple pattern to a flame after the Hashira Training Arc. This mark then stays with the same design until the story’s finale.
Tanjiro’s condition was like Kokushibo’s when he got transformed into a demon due to Muzan’s poisoning. Tanjiro, like him, was a great swordsman who became a demon. However, Tanjiro received additional patterns like the Demon Slayer Mark.
At his demon state, Tanjiro has three flame marks. The one on the left grows and falls down his nose, and the two on the right side of his face are smaller. One is on the opposite side of his usual mark, while the tiniest one begins at his jaw. While there is no way of knowing if they are Demon Slayers Marks, their similarity is obvious.
This will depend on the context of the question. If it involves all the Demon Slayers throughout history, it is safe to assume that Yoriichi Tsugikuni could easily defeat Tanjiro. However, for the Taisho Era, Tanjiro’s period, he is considered the strongest Demon Slayer.
Tanjiro went through a gradual and dynamic growth and evolution that transformed him from a little kid to a powerful Demon Slayer capable of defeating Muzan. At this point of the story, Tanjiro has enhanced physical capacities and incredible mental strength, as well as having mastered the Hinokami Kagura (the Sun Breathing Technique), having access to the 13th form of this technique, allowing him to prolong his abilities of Selfless State, the Crimson Blade, and Transparent World.
Just like the Hanafuda Earrings, Tanjiro’s scar is much more than a look trait. This mark is, just like Hanafuda Earrings and the Crimson Nichirin Blade, something strongly associated with the practitioners of the Breath of the Sun and allows the one who possesses it access to an incredible power that can match the Twelve Kizuki’s and Muzan’s strength and capabilities, allowing Tanjiro to finally defeat them by the end of this story.