Is Tanjiro a Demon in Demon Slayer (Manga & Anime)

Demon Slayer: Kimetsu no Yaiba has a lot of interesting characters to note. The two siblings, Tanjiro and Nezuko, are some of the most loved characters. Since Nezuko became a tamed demon, does Tanjiro also become like his sister in anime and manga?

Tanjiro is not a Demon in the manga or anime. However, he briefly became a demon by Muzan in the manga but was luckily cured by his friends’ efforts. All demons start as humans, but they get turned into demons when exposed to a demon’s blood.

In this article, I’ll explain what happened to Tanjiro when he briefly became a demon and the origins of demons according to the Demon Slayer series. I’ll also talk about how Nezuko turned human again and how she managed to remain human after getting re-exposed to a Demon’s blood.

Did Tanjiro Turn into a Demon in the Manga?

When Tanjiro “died,” Muzan, as a last-ditch effort, transferred his blood and emotions into Tanjiro, turning him into a demon. Similar to Nezuko, as a demon, Tanjiro built up immunity to sunlight after awakening. According to Muzan, Tanjiro could be the next Demon King.

Thankfully, Tanjiro’s comrades managed to inject him with the cure, and he was able to return to human again.

How Did Demons Come to Be?

All demons were originally human who got turned into demons via another demon. Muzan is the first of the demon race. Muzan was originally an extremely ill human. He was diagnosed with a disease that would eventually kill him before even reaching the age of 20. A doctor tried to cure him by giving him his prototype medicine. Unfortunately, the treatment seemingly did not work, so Muzan killed the doctor in a fit of rage. 

After killing the doctor, he realized that the medicine did work; however, it took away his humanity. To survive, he needed to consume human flesh and stay away from the sunlight. After discovering his weakness, he regretted killing the doctor because he failed to finish the Blue Spider Lily medicine that should have made his body withstand the sunlight.

Muzan created other demons by giving other humans their blood. He made an army of demons to find the Blue Spider Lily so he could get the perfect immortal body. Demons can also turn other humans into Demons by giving them their blood.

Why Did Nezuko turn into a Demon?

Muzan visited Tanjiro’s home in the hopes of creating a Demon that could withstand sunlight. However, Tanjiro’s family died of his blood poisoning instead. He failed to realize that Nezuko managed to survive and became a successful demon.

Unlike other demons, Nezuko was able to retain most of humanity. She also can walk in broad daylight in later parts of the series. Nezuko also refuses to eat humans. Instead, she regains her strength by sleeping.  

Why Didn’t Nezuko Turn into a Demon When Tanjiro Bit Her?

After turning back into a human, Nezuko rushes to save her brother Tanjiro from becoming one. A bit too late, Tanjiro was already a demon by the time she arrived. Instead, she tries to convince her brother to stop attacking the other Demon Slayers by using her own body to halt his movements. In a fit of anger, Tanjiro bit her. 

The bite Tanjiro did on her should have been enough to turn her back into a demon. However, it turns out Nezuko developed immunity towards Demon blood. It was revealed in chapter 204 that it was lucky Nezuko was the first and only person Tanjiro bit.

Because Nezuko was a demon before who managed to return to being a human. Her body developed antibodies that made her immune against Muzan’s cells.

What Happened to the Demons after Muzan Died?

Due to the efforts of the Demon Slayers in the Infinity Castle, most of the stronger Demons were eliminated. Muzan was also defeated by getting burned by the sun. With his defeat, the demons he created died. Only Yushiro and Chachamaru are left from the entire Demon Race. In chapter 205, Yushiro is still present in modern-day Japan as a painter.

Did Everyone Forget about the Demons in Present-day Japan?

Due to the nature of the demon’s decomposition, there were no remains to prove that there were demons in the past. There were also no historical documents that were made. In the end, present-day Japan has no clue about the demons.

As of chapter 205, it seems like the Kamado household still tells tales about the efforts of their ancestors. Tanjiro’s descendant, Sumiko, is a firm believer in the Demon Slayers’ fight versus Muzan.

Yoshiteru, also believes in the stories of a demon, having found Zenitsu’s journal that recounts the fight of the Demon Slayers against Muzan. However, the rest of the descendants and reincarnations seem to have no idea of their ancestors fighting. Instead, it looks like they treat the story as a fairy tale.

While there are no known written records, an account of the fight was written by Zenitsu is found with his ancestors. Also, the Kamado household is housing Tanjiro’s Nichirin blade, hanafuda earrings, and a photo of the Demon Slayer Corps after the battle of Muzan.

Why Couldn’t Muzan Find the Blue Spider Lily?

Muzan tried to find the Blue Spider Lily because it was the key to perfecting his immortal body. The Blue Spider Lily medicine is supposed to grant Muzan the ability to walk in daylight. However, Muzan could never find the flower, even with the army of demons.

Aoba Hashibara, Inosuke’s descendant, was a botanist who was able to find samples of the Blue Spider Lily. In her report, she learned that this flower only blooms during the daytime, two or three days a year. In addition, the Blue Spider Lily only stays in bloom for a short period and then closes up again. In its closed-up state, it looks like a horsetail weed.

This would explain why Muzan could not locate the flower even with an army of demons. None of them would be able to even identify it since it only blooms during the day.