Demon Slayer

Tanjiro Kamado is a young boy who returns home to find his family massacred. His sister, Nezuko, is the sole survivor but when he tries to save her, she transforms into a Demon and attacks him. A nearby swordsman, almost kills Nezuko, but spares her after noticing she is different from other demons. Tanjiro goes on to learn how to slay Demons and becomes a member of the elite Demon Slaying Corps. Tanjiro and Nezuko are then thrown into a world of danger as they hunt down Demons, search for a way to transform Nezuko back to a human, and track down the monster responsible for killing their family.