It is the Taisho Period (i.e. 1912-1926). Tanjiro Kamado is living a modest but blissful life in the mountains with his family. One day, when he returns from selling charcoal in town, he finds the remains of his slaughtered family in pools of blood after a demon attack. Tanjiro rushes down the snowy mountain with the sole survivor, his sister Nezuko, on his back. But on the way, Nezuko suddenly snarls, turning on Tanjiro.

To pass Final Selection, one must survive for seven days on Mt. Fujikasane where demons captured by the Demon Slayers have been imprisoned. So begins the battle for survival between the young swordsmen and the demons. Armed with the breathing techniques and stances he'd learned from Sakonji Urokodaki, Tanjiro slashes demon after demon. His two years of training have not gone to waste. But just then, a morphed demon appears out of nowhere.

The next mission is in Asakusa, Tokyo. Tanjiro is taken aback by the opulent Taisho Era cityscape, but soon picks up the demon’s scent there. His pursuit of the scent leads him to Muzan Kibutsuji. Tanjiro attempts to strike him down. But Kibutsuji transforms a passerby into demon, triggering a commotion. As Tanjiro desperately tries to get things under control, someone appears before him...

Tanjiro and Inosuke battle the Demon Slayers trapped by spider webs. After slashing the threads and destroying the webs, they head deeper into the mountain. The farther they advance through the forest, the thicker the threads become, and those under their control start moving in ways impossible for a human being. Stopping the Demon Slayers without hurting them isn't going to be easy, but then Tanjiro makes a certain move...

When Rui assaults him with his Blood Demon Art, Tanjiro braces himself for certain death. As his life flashes before his eyes, he suddenly remembers his father's dance, the kagura, and unleashes a new, non-Water Breathing attack. Hinokami Kagura Dance. Knowing that he’ll be receiving a simultaneous blow from the demon, he uses his new move to slice off Rui’s head. As Tanjiro crawls towards Nezuko, who lies on the ground, riddled with wounds, someone appears before him.