Ushio Aotsuki is a persistent middle school student who refuses to accept his father's warnings about the existence of youkai, supernatural monsters. While alone in the temple, he discovers a startling scene in the basement - a formidable youkai impaled by the legendary Beast Spear. The creature is Tora, widely known for its immense power, who urges Ushio to release him from his 500-year confinement. However, Ushio is hesitant to free him despite Tora's pleas. Nevertheless, when a surge of youkai begins to threaten his home and loved ones, Ushio has no choice but to rely on Tora and the ancient spear for survival. Their strange journey into the spiritual realm commences as Ushio, wielding the all-powerful Beast Spear, gradually learns the true and dreadful nature of the paranormal world.