Four hundred years ago, the ninja and the Yokai had a great war. The legendary Sarutobi Sasuke and four other ninjas sealed the Yokai Commander Nurarihyon and all his Yokai's energies away in a cave protected by the "Seal Door". In the present, one of the few remaining Yokai, Kappa, tricks Sarutobi Sasuke and Kirigakure Saizo's descendants, Saizou and Sasuke, into releasing the Yokai by opening the "Seal Door". Now these two, joined by three other descendants of great ninjas, become the KakuRangers to fight the reinvigorated Yokai with the aid of the Sanshinshou. However, the KakuRangers have their work cut out for them as the Youlkai are slowly being united under one banner.
