Based on the erotic game by Type-Moon.Emiya Shirou is a highschool boy who lives in Fuyuki City. His parents died in a fire when he was young, and he was adopted. The man who adopted him referred to himself as a magus, and Shirou greatly admired him, but he eventually also died. Now, unbeknownst to him, Fuyuki City will become the place of a great war, a fought in secret by magi like the man who adopted him.When the time is right, seven magi from near and far will gather together for this war. Each magus is a Master, and each master summons a Servant, a summoned spirit of a hero so mighty they exist outside of time. Together, Master and Servant will fight against the other teams for the possession of the Holy Grail, a relic said to be almighty and grant wishes. In order to allow the winning Master and Servant to be granted one wish each, all other teams must be defeated, and the enemy Servants annihilated. That is the Holy Grail War. The true names of the Servants reveal their weaknesses, and so they are usually referred to by their classes: Saber, Archer, Rider, Berserker, Lancer, Caster, and Assassin. Now it is time for the 5th Holy Grail War to take place.One night, Shirou witnesses a fight between two servants, Archer and Lancer. To preserve the secrecy of the War, Lancer mortally wounds him. However, a girl who up until now seemed a normal classmate of his, Toosaka Rin, saves his life using a magical pendant. On his way home, he gets attacked by Lancer again. Just before he's about to die for good, the Servant Saber is summoned. After driving Lancer off, the powerful sword user asks "Are you my Master", much to Shirou's bewilderment. In spite of being just an amateur, he now has to fight a war between powerful magi.