Four hundred years ago, the ninja and the Youkai had a great war. The legendary Sarutobi Sasuke and other four ninja sealed the Youkai Commander Nurarihyon and all his Youkai's energies away in a cave protected by the "Seal Door". In the present, the only surviving Youkai, Kappa, tricks Sarutobi Sasuke and Kirigakure Saizo's descendants, Saizou and Sasuke, into releasing the Youkai by opening the "Seal Door". Now these two, joined by
