It was first aired on January 30, 2005 and aired its final episode on January 22, 2006 and ran for 48 episodes.

Throughout Japanese history, there have been people who undergo intense training to use the purity of sound to transform into beings known as Oni to battle monstrous creatures known as the Makamou. Asumu Adachi, a student ready to transfer into high school, is unsure as to how he should proceed in his life when he meets a man only known as Hibiki, one of the Oni. Hibiki takes Asumu under his wing and trains him in the way of the Oni in the fight against the Makamou, joining fellow Oni Ibuki and Zanki and their apprentices.