Tanjiro is a Demon Hunter whose main objective is to find the person responsible for killing his family and turning his sister Nezuko into a Demon and then vowed to defeat Muzan Kibutsuji,the King of Demons,to avoid that others suffer the same fate as him.Before becoming a Demon Slayer,Tanjiro was a charcoal burner before Muzan killed his entire family while his younger sister,Nezuko,became a demon.