Chapter Text
As the sunset began to slowly make its close, the land was becoming dark. Normally, this would be the time to eat supper, enjoy time with family, before heading to rest and sleep until the sunrise came. But not on this land. The demons roamed at night, terrorising and devouring any human they could come across. The only hope for these people was the Demon Slayer Corps. But unfortunately, they could not cover all ground. They could not save everyone.
This was demon territory, and if a slayer were to enter the area, they would be immediately attacked in the safety of the moon.
The safety of the moon.
A once warm soul, who had a heart that would beat like any normal human’s, who had a family that he had abandoned, who lost his only brother to his own rage. A stone cold soul, that never had even cared for anyone at this point, was wandering the paths of this forest. He had been after a certain demon hunter that was in the area. This was no ordinary demon hunter, it was a Pillar. The most powerful of the corps.
He had been deployed to find this Pillar and dispose of him before he could reach any further heights. He continued walking, remembering the words of his Master. All that ran on his mind was ridding of this human filth, and returning successful.
Two days earlier...
There he was, on one knee, bowing down to his Master. Muzan Kibutsuji. “Kokushibou. You are my most powerful and trusted of the Twelve Kizuki. You have done much more for me than anyone has ever done before. Now I ask of you one simple task.”
Kokushibou looked up at his Master, awaiting the order.
“There is a pillar that has been sighted in this area. You must rid of them. I will give you a map, to lead you to this forest.” Muzan said, bringing out a rolled sheet of paper.
“I do not need that, Master. I know that forest well. I will find this Pillar. I will make sure they never see the light of day again.” Kokushibou replied. In turn, Muzan moved quickly to Kokushibou’s side.
“Stand, Upper Moon One.”
Kokushibou stood, but he felt no pride in that title.
Muzan rested his hand on the other’s shoulder. “Do not disappoint me. I expect success from you, always.”
“Yes, Master.”
And everything seemed to go dark, before Kokushibou found himself in a small shack. His journey to find the Pillar had begun.
Two Days Later...
His quiet and careful footsteps made no sound as he trekked the paths of the forest. He continued to peer through the trees, wondering if the Pillar had known that he was being hunted now.
”Impossible, I have the upper hand. There is absolutely no-“
His thoughts were cut off quickly by the whiff of blood he picked up. It was coming from the west. He swiftly turned and made his way down a small path that was lined by thick trees. And before he knew it, he was nearing the source of the smell. “It’s human blood.” He said to himself. Could this have been the Pillar, possibly injured? He rounded a small corner of trees, before he heard it. The faint crying of a child. A demon was crawling on the ground, it’s head nearly decapitated by woodworking fools. It was sloppy, there had been blood everywhere.
Kokushibou merely watched as the demon crawled inside of the house. He swiftly walked behind it, suddenly hearing a scream. The demon was nearing a young boy. The boy was trying to kill the demon again with woodworking tools. Before the demon could attack in return, Kokushibou quickly ended the demon’s life, saving the boy. He had killed his own kind. It was useless anyway. The demon was going to die either way.
The crying continued, and then he noticed the young boy holding another, identical one’s hand. He was sobbing. They were brothers. Twins.
Kokushibou regained a flood of memories. Memories that he had not always taken kindly to. Being beaten by his father for talking to his younger twin brother. The flute. The smiles. The jealousy. The hatred. The ability to not let go.
The other boy was already dead, from blood loss. His arm had been torn off by the demon. Kokushibou sighed. “That was impressive.” Before long the boy looked in horror as he saw Kokushibou, immediately grabbing a large pot that was next to him and throwing it at Kokushibou’s face. Yet, he dodged it.
”Why is this boy giving off a different aura.. it almost reminds me of my bloodline’s aura.”
“What is your name?” Kokushibou asked.
The boy clenched his teeth and didn’t say a word, still grasping one hand to his deceased brother’s.
“Hm, you don’t have to tell me.” Kokushibou said in turn. He then faced the door, and simply walked outside. He still needed to find the-
“Muichiro.”
Kokushibou stopped.
“Muichiro Tokito.”
Kokushibou turned around as the boy was now a few meters behind him. “Tokito. I see the Tsugikuni name has died out then.” This boy, was his very descendant.
Muichiro looked at him in confusion, wiping his tears from his swollen eyes. “What does that mean..”
“I am..” He stopped. Wondering if he really should tell this boy the truth. He then stayed silent and decided to keep moving. But he couldn’t just leave him behind. Kokushibou sighed.
”He is my descendant, surely. And he’s likely the last one left. Damn. I can’t leave him here. This is an opportunity.”
Kokushibou fully turned to face the younger. “Do you have anywhere to go?”
Muichiro was still wiping away his tears from his small cheeks. “No, I do not.” He said, the sadness clear in his voice.
Kokushibou looked at the ground. “He will kill me for this.” He sighed, and beckoned for the boy to follow him. “Come with me then.”
Muichiro looked back. “I need to bury my brother, please?”
Kokushibou looked at the moon, it was about 2 AM. There was time. “Hurry then.”
Kokushibou assisted Muichiro in burying his brother, Yuichiro. They gave a small moment of silence to the boy’s early death, and set out. Little did he know, Kokushibou now had more on his plate than he could handle. It was only a matter of time before this one mistake, saving a human child, came to his Master’s attention.
It was the beginning of Upper Moon One’s betrayal.