The ancient demon clan Water God Xiang Liu was sealed under the Yangtze River by Dayu due to the flooding of Kyushu. A trace of his soul escaped and transformed into a nine-headed insect. During the journey to the west, he was defeated by Sun Wukong and Yang Jian by cutting off one of his heads. After that, he fled eastward to Japan and became the famous Yamata-no-Orochi in Japan.
Thirteen hundred years later, Yamata no Orochi awakens, and a new journey between good and evil begins again.