Demon Slayer (My version)

Tanjiro Kamado, a young boy living in Japan who becomes the sole survivor of his family after demons kill them. He sets out to save his sister Nezuko who has transformed into a demon.
On Tanjiro's adventure he trains with a talented retired demon slayer to enter the demon slayer core. At the demon slayer core he is in a group with a demon named Rui who they become very close to each other.
On his adventure he goes through difficult challenges and obstacles in order to achieve his goal. On the way achieve his difficult goal that no one knows if it is possible he meets friends on the way.
He hopes to one day kill Muzan Kibitsuji who is the one responsible for killing his family.
Kibitsuji is very well know for living over 1,000 years, turning people into demons and for disguising himself into others.

Will Tanjiro make it out alive to turn his sister back to human? Or will world peace between demon and human happen?