Shinichi runs away from his problems and the people he fears. When Shinichi prays to the great Kawakami oak tree for courage, he is plunged into ancient feudal Japan. He awakens in the province of Kasuga, in the midst of a battle. It is there he meets the great warrior samurai, called the Demon Ijiri. Ijiri is a worthy adversary in battle, but he proves to be a less successful lover. He has been in love with Princess Ren since his youth. She has fiercely loved him in return, rebuking offers of marriage in the hopes of marrying for love.

When the powerful Lord Takatura asks for her hand in marriage, she dares not refuse him for the safety of her kingdom. When Shinichi's family emerges from the future to search for him, they bring stirring news to the town elders. The Kasuga province had never been recorded in history, and their enduring battles with other clans were seemingly fruitless. In light of this news, Princess Ren is relinquished of her duty to marry the formidable Lord Takatura. Ijiri is overjoyed, as is the Princess Ren. Yet Lord Takatura is unaccustomed to rejection, and his rage results in a fearsome battle.