For centuries, the Demon Slayer Corps has sacredly kept the location of Swordsmith Village a secret. As the village of the greatest forgers, it provides Demon Slayers with the finest weapons, which allow them to fight night-crawling fiends and ensure the safety of humans. After his sword was chipped and deemed useless, Tanjirou Kamado, along with his precious little sister Nezuko, is escorted to the village to receive a new one. Meanwhile, the death of an Upper Rank Demon disturbs the idle order in the demon world. As Tanjirou becomes acquainted with Mist Hashira Muichirou Tokitou and Love Hashira Mitsuri Kanroji, ferocious powers creep from the shadows and threaten to shatter the Demon Slayers' greatest line of defense.

After a string of mysterious disappearances begin to plague a train, the Demon Slayer Corps' multiple attempts to remedy the problem prove fruitless. To prevent further casualties, the Flame Pillar, Kyoujurou Rengoku, takes it upon himself to eliminate the threat. Accompanying him are some of the Corps' most promising new blood: Tanjirou Kamado, Zenitsu Agatsuma, and Inosuke Hashibira, who all hope to witness the fiery feats of this model demon slayer firsthand. Unbeknownst to them, the demonic forces responsible for the disappearances have already put their sinister plan in motion. Under this demonic presence, the group must muster every ounce of their willpower and draw their swords to save all two hundred passengers onboard. As things begin to spiral out of control, Tanjirou's resolve and commitment to duty are put to the test.

Kyousuke Kasuga is no stranger to being the new kid at school. Despite only being a third-year middle schooler, he has spent his entire childhood avoiding those who discover his family's paranormal powers, and he has had to change schools seven times as a result. Upon catching a beautiful girl's hat, he becomes optimistic and hopes that he and his family have finally moved for the last time. When Kyousuke gets to school, however, he learns a different story. The elegant girl he just met turns out to be none other than Madoka Ayukawa—also known as Madoka the Pick—a delinquent known to smoke, drink, and get into fights. Her best friend is first-year Hikaru Hiyama, a childish and energetic girl who quickly falls in love with Kyousuke. Enamored with both girls, Kyousuke tries to balance a delicate triangle of emotions, all while dealing with the antics brought about by a family with paranormal powers.

Ever since the death of his father, the burden of supporting the family has fallen upon Tanjirou Kamado's shoulders. Though living impoverished on a remote mountain, the Kamado family are able to enjoy a relatively peaceful and happy life. One day, Tanjirou decides to go down to the local village to make a little money selling charcoal. On his way back, night falls, forcing Tanjirou to take shelter in the house of a strange man, who warns him of the existence of flesh-eating demons that lurk in the woods at night. When he finally arrives back home the next day, he is met with a horrifying sight—his whole family has been slaughtered. Worse still, the sole survivor is his sister Nezuko, who has been turned into a bloodthirsty demon. Consumed by rage and hatred, Tanjirou swears to avenge his family and stay by his only remaining sibling. Alongside the mysterious group calling themselves the Demon Slayer Corps, Tanjirou will do whatever it takes to slay the demons and protect the remnants of his beloved sister's humanity.