32 years later…
In the Shōwa Era, around midnight.
A 6-year-old kid is running away from someone. The kid is weeping uncontrollably, running away with all his might. Something is chasing after him.
That's a demon.
The demon is chasing him, more likely playing. It has long and sharp teeth and has worn some formal, western clothes. Its athletic physique makes it even scarier.
The other two demons join him as well, they're his servants. In a sudden, two more demons join and chase the boy.
"We're here, master!" the other two demons exclaimed.
Under the full moon, chilling gales sweep through the dark, amplifying the terror. The boy stumbles forward, directionless, driven only by the desperate urge to survive.
"How unlucky~ You can't run away from me. Run faster, kid. Hahahahah," the demon laughs.
———————————————————————
A few hours ago.
At midnight.
The boy went outside of his house, not so far away. He has a wooden house amid the forest, isolated from other people, which is enough for his family to live. His entire family, including his two younger brothers, two younger sisters, and his mother, are sleeping.
"I should go back, or else mom will scold me again for wandering alone in the forest," he thinks.
Whenever he doesn't sleep, he wanders around. With the belief that walking in the moonlight may help him fall asleep.
When he reached home, he felt too unpleasant. He smells something weird, his sense of smell is extraordinary. It's something he doesn't want to accept.
It was blood.
He slowly pushes the Shoji door, careful not to make any noise to disrupt anyone's sleep.
When he opens the door, blood comes out from the inside. The wooden floor is messed with blood, his family lay down there, lifeless and torn up.
His eyes widened in horror when he watched a demon devouring upon his family. He covers his mouth with his hand, making sure not to make any noise.
Tears streaming down his cheeks.
"Don't watch me like that, kid," says the demon without turning his head towards him.
Before the kid could do anything, the demon instantly turned his head to face him.
———————————————————————
In the present time.
The kid is still running as fast as he can. He runs out of his stamina, unable to walk anymore.
He finds a temple before him.
A historic temple dedicated to the goddess of mercy.
When he comes near the temple, he falls to the ground. His stamina runs out.
The demon slowly approaches the kid in a menacing walk. The kid crawls toward the temple, trying to escape the demon with all his energy left. He picks up some stones from the ground and throws them at him.
But there's no use of it.
"Do you really think you can get away from me by doing these cheap things? Why don't you die and meet your family in Heaven?" the demon says in a sarcastic tone.
"W-Why did you kill everyone..? Why?!!" he sobs.
"Hahah… Don't you get it yet? I am a demon, and I'll do whatever I want," the demon laughs.
The kid is crying loudly. The sight of him melts the heart of the other two demons.
One of the demons, a female demon, says politely.
"Takeshi-Sama, I apologize but can we leave this kid alone?"
"Are you stupid? Don't you even know what are you saying? We are demons. We can't let anyone escape," says Takeshi furiously.
The other two demons remember their past. Some days ago, they were living a good life with their family. But then, Takeshi showed up and slaughtered their family. They wanted to live, so Takeshi took them to the current demon king and turned them into demons.
"Listen, kid. There's nothing like a family, and love doesn't exist. You can't live in this world with the power of love alone. Once they die, they end up in nothingness. No one will stay with you forever," says Takeshi in a stern voice.
"You're wrong. Didn't your family love you? Now, you're ruining others' families," sobs the kid.
Takeshi feels a sense of guilt. He never thought a kid would prove him wrong.
He remembers his past.
————
When he was young, he had a cruel and violent father. Meanwhile, his mother loved him so much.
He always felt lonely. He had no siblings or friends to play with. His father was a drug addict. His father would often beat his mother when he was drunk. Despite every domestic violence, his mother would endure everything for him.
When he was seven, his mother became extremely sick. As his father couldn't beat her mother anymore, he would beat Takeshi. His mother couldn't save him from his father's cruelty.
After two months, his mother passed away.
He became depressed, his mother was the only one who loved him. At his most crucial moment, his father ignored him. Some days later, his dad leaves the house for another wife.
It made him deceived that there was nothing like a family. Love is temporary.
————
When he comes out of his mind, he glares at the boy.
"Shut up, kid! You know nothing about this world. Don't act like you know everything," shouts Takeshi and lunges at him.
The two demons confront Takeshi and save the boy.
"You lowkey demons want to fight me? Have you forgotten your place, you fools? I am one of the twelve kizukis. I am the Lower Moon 6, Takeshi!"
"We won't make anyone suffer like how we suffered. We will save this kid even if it costs our lives," says the demons.
They both lunge at him simultaneously. But it was nothing for him, he effortlessly dodges their attacks.
"
He shoots a venomous beam at them, inflicting immense pain and melting their entire bodies.
The kid is frightened by his monstrous abilities.
"My subordinates died because of you. You are nothing but a curse, and I need to eradicate you from this world."
Takeshi instantly appears behind the boy. When he tries to attack him, the boy disappears from his sight.
"Huh?" Takeshi is dumbfounded by his unexpected disappearance.
When he turns around, he sees another kid around the same age as the boy, holding him in his hands. He gently puts the boy down to his feet.
Another child stands a short distance away, barely visible in the moonlight. He grips a katana that seems far too large for his tiny hands. His small frame is clothed in simple robes, but his presence feels unsettlingly still. The boy looks so innocent, so untouched by the cruelty around him, yet there's something strange in his expression, a void where emotion should be.
Long, dark hair cascades over his shoulders, framing his face, which seems to glow under the moonlight. His skin is smooth, unmarked by age or sorrow, but there is an odd mark etched into his cheek, faintly visible beneath the night's shadows. It's a demon slayer mark.
Hanafuda earrings dangle from his ears, glinting softly as they catch the silvery light. Their quiet beauty contrasts sharply with his vacant stare. Despite his young age, there's no glimmer of childish curiosity or fear in his eyes, no hatred, no sorrow, not even a spark of spirit. He stands as though untouched by life itself.
Takeshi shivers at the sight of his earrings. He doesn't know the reason.
"What a beautiful night it is. I'll eat two kids and become stronger."
He lunges at another kid, his hand only mere inches away from him.
Suddenly…
His arm disappears and suddenly falls to the ground. "What?!!"
His severed arm starts bleeding. The other kid is still standing steadily.
"What?!! I couldn't even see his attack. Could he be… a hashira? Hashira at this age, how is this even possible?" thinks Takeshi.
"Why do you hashiras run after us? We lower moons spend our whole lives hiding from you. You have no mercy upon us," says Takeshi.
He thought a kid could never understand his words. But then… the kid says in a cold yet calm voice,
"What do you mean by mercy? Do you think twice before killing any innocent? You demons kill people for power. Don't act innocent, you guys are called demons for a reason. You ruin countless lives, you show no mercy upon anyone. So why do we show any mercy upon you?"
And then…
He slices Takeshi's head in one, elegant swing.
His body starts crumbling into ashes…
…
"... I've never seen anyone like this kid in my entire life. Was I… wrong?"
He vanishes entirely from the world.
The first kid is shocked. He thinks that he has seen this demon slayer before, maybe somewhere else. No, it's not just a Deja Vu. He has seen someone like him wearing the same earrings.
"Where's your house?" asks the other kid in a calm voice.
"My house… my family… He…" his words are interrupted by his tears.
"I understand what happened to them. I am sorry for that… But there's no other way. Come with me, I'll tell you everything. We don't have enough time to talk."
The kid looks at him with teary eyes. He slowly nods as he runs away with him.
A few moments later, the demon king, Kokushibo arrives at the same place.
…
"How's this even possible? They've disappeared in no time. So the kid is no one but… him," thinks Kokushibo.
————
A few moments later.
The kids arrive at the demon slayer hideout. The first kid feels too tired, but his tiredness is nothing to his grief. He is still weeping, unable to overcome his grief.
The other kid comforts him.
He says in a calm voice, "Oh, I'm sorry I didn't ask about you. What's your name?"