The Holy Grail War is a death-match between 7 magi (Masters) and their summoned heroic spirits (Servants). In this battle royale, the prize is the legendary Holy Grail, said to be an omnipotent wish-granting device which will produce any sort of miracle in order to bend reality to accommodate the wishes it grants. The winning Master and Servant shall be granted one wish each, after which the Holy Grail will not be activated until the next War.
The 4th Holy Grail War is about to take place, and the 3 preceding Wars had ended without a victor. In pursuit of their individual goals and ambitions, the competing magi congregate at a Japanese city called Fuyuki. All the magi will do anything, rationalize away any atrocity, in pursuit of the Holy Grail. All of them, but one.
Kotomine Kirei is a Master, but one without a reason to fight. Unable to release himself from the threads of Fate, he is reluctantly drawn into the War. To enter the War, he even had to stray from his path in the Holy Church and join the ranks of the Mage’s Association, an organization with which the Church is not on good terms, but which it has to tolerate and sometimes even cooperate with.
However, as Fate would ironically have it, one of his rival Masters, Emiya Kiritsugu, is a man more merciless than anyone else, an assassin who killed many people and intervened in many conflicts, for reasons no one is able to understand. Kirei’s fight against this interesting yet strange sort of enemy might prove to be his most troubling task so far. Kiritsugu is equally puzzled by Kirei, and both of them still have the other Masters and Servants to take care of.