Shy, timid Himeko happily attends school with both the popular and beautiful Chikane and her childhood friend, Souma, blissfully unaware of what's in store for her.
However, the destiny of these three changes on Himeko's 16th birthday when the mark of the sun appears on her chest. What does this solar mark represent? At the same time, why has a black aura of agony burst forth from Souma? Who is the enemy? The legend of the eight-headed beast returns to Japan!