The story takes place in Huanli (the Year of Dazzling) 3015. Donatia and Kouran, two countries fighting for supremacy, are causing the world to be torn apart due to the constant war. Amidst the strife is the island country Nil Kamui, which has lost its independence. Red Dragon, the guardian god of Nil Kamui, goes out of control. Will the island country be able to regain its independence?
Kenshi Masaki is the half brother of Tenchi Masaki and used to live in Japan, that is until he was summoned to the land of Geminar. The Land of Geminar has been witness to an endless amount of wars that have been fought using Seikijin, bio-mechanical weapons controlled by a capable warrior called a Seikishi using magic power called Ahou. It is revealed that Kenshi is an amazing Seikishi and it seems someone has a reason for Kenshi to be in Geminar, but who and why are not known.
Enter Sentan, a lush, tranquil island encased in war between the military and those with Hiruko, known as X'amd. On one of these warlike days, Akiyuki Takehara heads off to school and gets caught in a raid by the creatures. Through a series of events he is transformed into a X'amd, and with the help of a Tessikan woman Nakiami along with his highschool friend Haru, Akiyuki is forced to learn to live with the Hiruko or faces the danger of losing his self-control and turn to stone.