Tanjiro Kamadon is a kind-hearted and intelligent boy living in the mountains with his family. After his father passed away, he becomes the family’s sole source of income. He earns money by selling charcoal to the nearby villages. One day when he returns to home and discovers that his family has been slaughtered by demons. The only one who survives is his younger sister Nezuko being transformed into a demon. Demons only kill humans to survive but Nezuko surprisingly shows signs of human emotions. Giyu Tomioka a demon slayer come to that mountain to kill the demons sees Nezuko protecting his brother. So Tomioka decides not to kill Nezuko and recruits Tanjiro to become a demon slayer. Tomioka sends Tanjiro to his former master and also a former Hashira named Sakonji Urokodaki. Tangiro trains under Urokodaki where he learns water style sword techniques.

Tanjiro becomes a demon slayer after passing the selection exam and begins his quest to search for a cure to change his sister Nezuko back to human. At the end of the test everyone who has passed the exam was asked to pick up an ore to make their demon slayer sword which was placed in front of them. Using this sword provided by the demon slayer corps. During a mission where is asked to investigate a village where young girls are being kidnapped. In that village he finds Muzan Kibuysuji who is the leader on a group of demons. Tamayo who is a demon as well as a doctor along with her companion Yushiro meets with Tanjiro and Nezuko. From them he learns about Demon Blood Art a powerful demon technique. And also explains about all demons contains Muzan’s blood and tracked by him. If any of the demons reveal about Muzan, their cells will be destroyed. This is called Kibutsuji curse.

Muzan seeing Tanjiro in the village sends demons to kill him. With the help of Tamayo and Yushiro defeats those demons. During Tanjiro’s next he meets Zenitsu and Inosuke who later becomes his teammates. Among the demons there are Higher-ups Upper Moons and Lower Moons. They together fights one of the lower moon demons named Rui. During the fight against Rui, Tanjiiro unleashes a technique Hirokami Kagura, which was passed down by his father. After the battle Tanjiro and Nezuko are taken to the headquarters of the demon slayer corps, where all the Hashira’s, who are the highest members of the demon slayer corps accept Nezuko. Later Tanjiro and his friends are taken care by Sinobu Kocho one of the Hashira in the butterfly mansion. There they trains to use breathing techniques. Ones they complete their training he gets new sword to replace the broken sword and goes for a new mission.