At the end of the Heian Era, mutated ghosts appeared one after another in the southeast corner, which is known as the strongest defense system against ghosts. What these ghosts have in common is a strong obsession and spiritual power that rivals hundreds of ghosts. Duan Keling, the most "unbelievable" student in the Yin and Yang dormitory (a freak who holds duck eggs in theory classes and gets full marks in practical classes), unfortunately falls into trouble again and again and has to embark on the road of no return with his colleague and friend Machi Kamo to eliminate mutant ghosts...