In ancient times, the water god Xiangliu of the demon clan was sealed beneath the Yangtze River by Yu the Great for flooding the Nine Provinces. After a fragment of his soul escaped, he took the form of the Nine-Headed Bug. During the Journey to the West, Sun Wukong and Yang Jian defeated him and cut off one of his heads. He fled east to Japan, where he became the famous Yamata no Orochi.
Thirteen hundred years later, the Yamata no Orochi awakens, and a new journey between good and evil begins.