Fuyuki City—a city surrounded by the ocean and the mountains becomes the setting for an age-old ritual. To realize the mythical Holy Grail, which is said to grant any wish from its possessor, seven masters are given seven heroic spirits chosen by the Grail. These heroic spirits or servants are: Saber, Lancer, Archer, Rider, Caster, Assassin, Berserker.
Each master will enter into a contract with their assigned servants and battle the other masters and servants to the death until only one pair remains...
This is the "Holy Grail War."
This story focuses primarily on the heroine Rin Toosaka. After her father's death, Rin enters the Holy Grail War as the sole heir to the prestigious Toosaka Household, with her servant Archer. But, she soon finds out that Shirou Emiya, a boy from her high school has gotten himself involved in the battles and unexpectedly saves him when he is fatally injured.
Before long, Rin sets out to strike down the conspiracies surrounding the Holy Grail War along with Shirou and his summoned servant Saber. And so, the story begins to explore the truth behind Shirou’s powers and the nature behind his unyielding will to become a "hero."