In Demon Slayer, the close and strong relationship that Tanjiro and Nezuko share with one another is the main driving force behind Tanjiro’s motivation to become a Demon Slayer. At the very start of the series, we find that Tanjiro’s family was murdered by a demon, with only his sister, Nezuko Kamado, being the only survivor. However, she was no longer a human as she was transformed into a demon.
In the earlier parts of the story, the only lead that Tanjiro had about his family’s killer was the scent that was left behind at his home. The demon who killed his family was also responsible for turning Nezuko into a demon, thus making him the primary target for Tanjiro.
After passing the Final Selection Exam and becoming a Demon Slayer, then completing his next mission, Tanjiro heads to Asakusa town and ends up face-to-face with the demon responsible for his family’s slaughter. It is revealed that it was no ordinary demon that killed his family and turned his sister into a demon; it was the king of the demons himself, the demon progenitor, Muzan Kibutsuji!
Why Did Muzan Kill Tanjiro’s Family?
Muzan Kibutsuji is the main villain of Demon Slayer, who was the first person to become a demon over a thousand years ago before the story began. He is well-known as the King of Demons, the oldest and strongest of all demons.
He is shown to be capable of turning anyone into a demon by injecting his own blood into the person’s body. And so, he is the progenitor of all demons in existence, which makes him control every single demon in existence and enables him to rule over them with an iron fist.
Despite his ability to turn people into demons, the process isn’t always successful, as their bodies can reject the transformation, resulting in them becoming horribly disfigured and dying.
His tendency to turn people into demons lies in his ultimate goal of becoming the perfect being which can’t be accomplished unless he manages to overcome a significant weakness all the demons share.
The motives behind Muzan’s keen interest in transforming regular people into demons like him align with his goal of conquering the sun.
All demons in Demon Slayer are afraid of the sun, as simply getting exposed to them will almost immediately kill them by disintegrating their bodies. Muzan is no exception to this weakness which he finds a great hindrance throughout his time as a demon and motivation to become as strong as he wants to be.
Because of this, there isn’t a solid and real reason behind Muzan’s attack on Tanjiro’s family and his attempt to turn Nezuko (and other members of the Kamado family) into demons besides his pursuit of overcoming his weakness towards the sun. At the time of Muzan attacking Tanjiro’s family, it can simply be presumed that it was out of coincidence and no personal vendetta despite the hatred that the two will have for one another.
We can imagine that during the night that Muzan attacked Tanjiro’s family, he was doing so to further his intentions of creating a demon that could survive the sunlight. He most likely attacked and killed Tanjiro’s family and attempted to turn them into demons, with only Nezuko surviving the onslaught and transformation.
Muzan’s dreams of overcoming the weakness demons share towards the sunlight eventually become a reality as Nezuko develops a resistance towards the sun later in the story, immediately catching Muzan’s interest. It only helped to boost his desire to have Nezuko for himself to be able to gain the same resistances she has towards the sun.
Contrary to what several people may think, as it is easy to mix up events from the story, Muzan never had a real reason to attack Tanjiro’s family as a personal vendetta against the siblings or the Kamado family.
Tanjiro and Muzan never met until their fateful meeting in a city where Tanjiro encounters Muzan. Muzan catches a glimpse of Tanjiro’s earrings and instantly develops a hatred towards him. Before this encounter, Muzan never knew about the existence of the Kamado family, even the fact that the earrings of the person who almost killed Muzan several centuries ago had been passed down as an heirloom by the family for the succeeding generations.
Muzan could’ve simply killed Tanjiro’s family out of the motivation to further realize his ambition to become the ultimate being, and it was just the perfect coincidence that the Kamado family was the only family keeping the Hanafuda earrings that Yoriichi was wearing when he encountered and overpowered Muzan during their fateful meeting.
Also Read: Who is Demon King Tanjiro?
