In Orario, fearless adventurers band together in search of fame and fortune within the underground labyrinth known as the Dungeon. But Bell Cranel, novice adventurer, has bigger plans than riches and glory; he fights monsters in the hope of having a fateful encounter with a girl. When this happens, it doesn't go exactly as he planned. Thus begins the story of an unlikely pair, a boy and a goddess, both trying to prove themselves, both eager to reach their goals.

In the Holy Grail War, seven magi chosen by the Holy Grail itself must summon seven Heroic Spirits to compete for the omnipotent Grail, a magical device that grants the victor any wish they desire. After three inconclusive wars, the fuse has now been lit once again for the fourth time.

Shirou Emiya lost his parents in a fire when he was young and was later adopted by the sorcerer Kiritsugu Emiya. Shirou is drawn into the Holy Grail War summons a female "Servant" known as Saber to protect him and obtain the Holy Grail.

This story focuses primarily on the heroine Rin Tohsaka. After her father’s death, Rin enters the Holy Grail War as the sole heir to the prestigious Tohsaka 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.”