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.
After civilization succumbs to a deadly pandemic and his wife is murdered, a special forces soldier abandons his duty and becomes a hermit in the Nordic wilderness. Years later, a wounded woman appears on his doorstep. She's escaped from a lab and her pursuers believe her blood is the key to a worldwide cure. He's hesitant to get involved, but all doubts are cast aside when he discovers her pursuer is none other than Commander Stone, the man that murdered his wife some years ago.
The Eternals are a team of ancient aliens who have been living on Earth in secret for thousands of years. When an unexpected tragedy forces them out of the shadows, they are forced to reunite against mankind’s most ancient enemy, the Deviants.