Shirou Emiya(Master):
Shirou is a good-hearted and honest teenager, who always enjoys helping others. He is in his second year of high school. He has no interest in the Holy Grail, and instead despises its use. However, he is determined to win the Holy Grail War with Saber, for he hopes his efforts will ensure that another disaster like the Fuyuki fire will never occur again. He is raised by his adopted father, Kiritsugu Emiya, who imparts on him basic sorcery, and the ideal of protecting the innocent. He believes that it is possible to save everyone without harming any innocents.
Saber(Servant):
Saber is Shirou Servant for the Fifth Holy Grail War. Loyal, independent, and reserved, Saber acts coldly but is actually suppressing her emotions to focus on her goals. Her class is considered the "Most Outstanding", with excellent ratings in all categories.
Rin Tosaka(Master):
Rin is a model student and idol of Shirou school. She barely talks to other students in her school and exhibits a desire to be left alone. She is also secretly a Magus, and a Master in the Fifth Holy Grail War, she summons Archer for her Servant.
Archer(Servant):
Archer is the Servant of Rin Tosaka. He is sarcastic and cynical, an individual skilled at creating imitations of objects through the use of tracing and projection of mental images to form tangible objects.
Illyasviel von Einzbern(Master):
A young homunculus(daughter of Kiritsugu Emiya and Irisviel von Einzbern) who travels to Japan to participate in the fifth Holy Grail War as the Master of Berserker. Illyasviel has an angelic appearance and an unsurpassed degree of magical power, seemingly able to control Berserker with ease.
Berserker(Servant):
The Servant of Illya, who appears as a swarthy giant with adamantine skin and gross brawn. He wields a colossal axe-sword, and is capable of causing massive destruction with the mere backlash of his swings. As a Berserker, he is stripped of his sanity and reason, acting feral and animalistic in combat. Berserkers are praised as members of the "Strongest" class, though they are difficult to control and can turn on their Masters.
Souichirou Kuzuki(Master):
The acting Master of Caster in the Fifth Holy Grail War. He is known as the strict homeroom instructor of Rin's class, who is not a magus, but He primarily lectures on World History, though he holds classes in Ethics. Kuzuki is well respected among staff and students.
Caster(Servant):
Caster is the Servant of Souichirou Kuzuki. Unlike other Servants, she does not wield a weapon for physical combat, but her rank allows her to manipulate Mana and perform magic like a wizard, something which other Servants cannot do. Her magical ability far surpasses modern Magi, due to her technique.
Shinji Matou(Master):
Master of Rider in the Fifth Holy Grail War of Fate/stay night. he has been a friend of Shirou Emiya for a number of years. he is also of a distinguished lineage of sorcerers, though the Mato blood has thinned and no longer produces heirs naturally capable of sorcery.
Rider(Servant):
The Servant of Shinji. Rider is silent, sultry, and vigilant, never hesitating to shield her Master from harm. She fights mainly with a Nameless Dagger and employs covert battle tactics and takes full advantage of her surroundings.
Kirei Kotomine(Master):
Master of Lancer. the supposedly impartial mediator during the Fifth War(Watch Fate/Zero for his back-story).
Lancer(Servant):
Servant of Kirei Kotomine. Lancer is a fierce but balanced warrior who enjoys combating a worthy opponent. He wields a red spear which inflicts wounds that do not heal. When activated, it reverses the laws of cause and effect.
Assassin(Servant):
A solitary Servant, clothed in a traditional Japanese hakama and kimono with an indigo haori.
Back story Spoiler:
Servant of Caster. He was summoned by her as a guardian and watchman for the front gate of the Ryuudouji Temple. As an improper servant, Assassin is entirely dependent on Caster for mana and cannot move freely beyond the grounds of Ryuudou Temple.