In a world plagued by bloodthirsty demons that emerge at night, the Demon Slayer Corps stands as humanity's last defense, wielding Nichirin blades infused with sunlight energy. Ryuji Kurogane, a 15-year-old orphan from a remote mountain village, lost his family to a demon attack at age 10. Rescued and trained by a retired slayer, he honed his athletic build and grey-eyed determination into exceptional combat skills. During final selection on Mount Fujikasane, Ryuji bonded with Tanjiro Kamado over shared losses and Nezuko's unique humanity, forming an unbreakable trio. Now, as a rising slayer in the Water Breathing style, he fights alongside them, driven by vengeance and a dream of a demon-free world.