The son of the demon king

Life at the infinity fortress

Years had past since muzan brought tanjiro back to the infinity fortress, the first year with tanjiro was smooth............i said it if it were true, it was quite chaotic as muzan and the upper moons had zero experience taking care of a child let alone raising one

So muzan had to go out and read books on taking care of a child since he and other moons knew nothing especially since they gone for years without knowledge of taking care of a child or anything a human needs to survive

So the years when tanjiro was a baby were the chaotic and wholesome years, those years were the upper moons and muzan's years where they took turns taking care of tanjiro

Akaza and kokushibou eventually warmed up the to tanjiro and played with him, eventually tanjiro got older and was now 6 years old. Running around the training room tanjiro reached his hand out and tagged akaza

"Got you!"
"Ahaha! You gotten faster!"

Akaza then brought tanjiro into a hug as tanjiro hugged him back, they were playing tag as it was part of tanjiro training to be a spy for muzan in the demon slayer Corp

Part of tanjiro's training was being trained to have a bigger stamina to run longer distances so when kokushibou trains him he will be able to use breathing techniques easier

After that doma taught tanjiro about a regular education and other things but tanjiro preferred nicknames for everyone as muzan became father, daki as mother, kokushibou as uncle koku, doma for uncle doma and akaza as big bro

Daki would sing tanjiro a lot in his younger years and her brother gyutaro wasn't really pleased with tanjiro being in the infinity fortress but that all changed when tanjiro was 3 years old

Le flashback

Daki was once again singing to tanjiro asleep as he was 3 years old, her brother gyutaro had gone out for months on end to get a large supply of flesh for him and his sister to eat so she wouldn't have to hunt for her meal

He got back with a large sack full with flesh and dripping with a bit of blood, gyutaro saw his sister singing a lullaby to tanjiro who was currently sleeping in her lap with a blanket keeping them warm

He walked up to them but scoffed at at tanjiro

"What are you doing with this brat?"

Gyutaro didn't really like tanjiro as he had to waste a lot of time for him and his fellow moons to hunt more flesh but after a few years everyone had loved tanjiro and would gladly lay down their lives to protect him

Gyutaro being the last one to not accept tanjiro was due to tanjiro caught staring at gyutaro who would turned to face him but saw him run back to his room which made gyutaro think he feared him and thought tanjiro might be thinking he was ugly

Gyutaro had been ugly since birth and it was the main reason that his sister died due to the fact that nobody helped him since he was 'ugly'

"Don't you dare call tanjiro that!"

Daki whisper-yelled as she looked at her older brother with a bit of anger

"Well it's not my fault I don't like him! He always runs away from me every time I look at him! He finds me ugly!"
"We've been through this time and time again, your not ugly!"
"Yes I am! If I weren't ugly then you wouldn't have been killed!"

The two were about to argue but tanjiro's cutely yawned as he rubbed his eyes and saw gyutaro, gyutaro looked at him with anger as tanjiro smiled at him

"Heh? What's with the smile?"
"Your mothers brother right?"
"Yeah? You think we don't look alike?"
"I already knew you two were siblings! Wait! I got something for you!"