Demon Slayer: Kimetsu no Yaiba: Season 1 (2019) 6.520
It is the Taisho Period in Japan. Tanjiro, a kindhearted boy who sells charcoal for a living, finds his family slaughtered by a demon. To make matters worse, his younger sister Nezuko, the sole survivor, has been transformed into a demon herself.
Though devastated by this grim reality, Tanjiro resolves to become a “demon slayer” so that he can turn his sister back into a human, and kill the demon that massacred his family.