Prologue: Son of the King

Muzan Kibutsuji, hates the line of Yoriichi Tsugikuni. The one man... he fears.

Even after Kokushibo informed him that he died of age, he knows that there must be someone else sharing his blood. And once he found them... they will pay the sins of their ancestor. And he has a name to look.

Kamado.

That's the reason he is in this town now. According to his sources the Kamado's should be living here. The town is preparing for the New Year and the streets were busy. And among them, there was a teen trying to sell coal.

Looking at him, he feels his blood boiling. That red hair is familiar. Just as those hanafuda earrings.

The veins on his forehead popped and his eyes widen in rage. He walked to him as he was spotted "Hello Sir, do you need some coal?"

"What's your name?" The teen looked surprise by the question but kept smiling, a friendly smile, unaware he is about to die.

"Tanjiro Kamado." Muzan felt his hand twitch in annoyance. He found him... he will end Yoriichi's line now! "I haven't seen you in town before Sir, may I ask your name?"

Tanjiro watched how the well-dressed man didn't answer and grew worried "Are you feeling well?"

Muzan kept glaring at him. He was about to strike, when... he got an idea. If this child is even half as strong as Yoriichi... he can have him as his own.

Muzan smiled kindly at him "Yes, you just reminded me to someone I knew. My name is Muzan child." He looked around as people walked without even noticing Tanjiro "Why are you working so hard to sell this coal? While instead you could be with your family."

Tanjiro looked at the ground "Well, after my father passed away, I am the one responsible for bringing money to my home. And now... mother fell sick. I can't rest now."

"How noble." Muzan hummed "Your family must be lucky for having you." He praised "How much does the treatment cost?"

Tanjiro looked at the ground "A lot. I haven't been able to sell a lot of coal... but still! I know I will get the money!"

Muzan smirked "I can help you then."

Tanjiro eyes widen in joy "Really?"

Muzan nodded "I ran a company far away from here. I was looking for an assistant before this little vacation of mine. I am willing to pay the whole treatment of your mother in advance if you work for me."

Tanjiro gulped. If what he is saying is true... he can save his mother now. Because he will get the money... but maybe it will be too late.

He nodded "I... I accept."

Muan smirked "Excellent." He took from his pocket a check and wrote 1,000,000 yens and handed it to Tanjiro shocking the kid "Give it to your family and say your goodbyes. We are leaving in before sunrise."

"We are leaving tonight?" Tanjiro asked and Muzan nodded.

"Yes. We have important business to do, Tanjiro. Now hurry up."

Tanjiro rushed to his home, where his siblings received him "Oni-Chan, how did it go?" Nezuko asked and Tanjiro nodded smiling.

"Great. I got the money. But... I have to leave."

After explaining what happened Kie nodded "I see... Tanjiro my son... take care... be happy and make other happy. And make sure to visit."

After saying his goodbyes, Nezuko huuged him "I will miss you, Oni-Chan."

Tanjiro hugged her back "I will miss you too. And I promise you, I will buy you the prettiest kimono I'll see."

Tanjiro looked from the window of the car how the village he grew in, got further and further away. He turned to Muzan. "So... in what does the job consist?"

Muzan smirk turned malicious. "It is simple..."

His hand went through Tanjiro's head as he pumped blood into him "Live and die for me... Yoriichi's legacy."

Tanjiro shook as... he died. His memories... started to get foggy.

Father dancing.

Mother's food.

His siblings love.

He promised Nezuko... the prettiest he sees.

Who is... Nezuko...

Muzan smirked as he saw Tanjiro skin turn white and his hair turn blood red. He removed his hand from Tanjiro's face as it healed. His crimson eyes turned into plum red and he had blue marks coming from his eyes.

"Tanjiro-Kun... how are you feeling?"

Tanjiro shook his head and looked at Muzan with a confused look. "Who... who are you?"

Muzan chuckled as he patted his head "Tanjiro," He grinned.

"I am your father."

Next Chapter: The Strongest Moon