Fourteen Breathing Styles were featured in the show, though only thirteen were officially recognized by the Demon Slayer Corps. But what if there was another Breathing Style that no one knew about? Driven by curiosity, Master Kagaya Ubuyashiki sent two Hashiras to investigate a mysterious village. For years, not a single demon had been sighted there, and there were no records of anyone disappearing due to demon activity. The Corps believed the village to be free of demons. But what they didn't know was that someone else had been protecting it, a Demon Slayer unknown to the rest of the world.