Fate/Prototype (フェイト/プロトタイプ, Feito/purototaipu?) is an animated short by Studio Lerche, distributed with the third home release of Carnival Phantasm on December 2011. Based around the Second Tokyo Holy Grail War, it is the original concept of Kinoko Nasu's for Fate/stay night. It has yet to be adapted as a full series, with only a short animated feature and production notes detailing the story. The prequel story Fate/Prototype: Fragments of Sky Silver has been fully adapted in drama CDs with the same voice actors and actresses.
The system of the War and everything else is much like that from Fate/stay night in some points, but unlike the produced project, the Prototype version has Masters that possess "Master Degrees", which are named following the angelic hierarchy starting from the 7th Order and up (so Princes, Powers, Virtues, Dominions, Thrones, Cherubim, Seraphim).
The storyline of Fate/Prototype takes place in its own universe, eight years after the tragic First Holy Grail War also known as the "Heaven's Feel" ritual. Here, the Holy Grail is still the so desired object. However, the darkness contained within the "Holy Grail" is gradually revealed as the characters proceed to struggle against each other in order to win the war.
The story begins with Ayaka Sajyou, a magus who is the last surviving member of the Sajyou family who tries to live her life as normally as possible, while avoiding any connection to her past and the Holy Grail War. However, Ayaka's destiny has been sealed since the day when her father and prominent older sister, Manaka Sajyou, were murdered during the First Holy Grail War, eight years ago. Even now, she can still remember the last thing her father said before his death "You have no choice but to enter into the Heaven's Feel".
On the eighth anniversary of the death of her family, Ayaka has a mysterious encounter with Sancraid Phahn who warns her that the Second Holy Grail War is about to begin and that she can't run away from it. Later that night, Ayaka is pursued by a mysterious man with vicious creatures, who stabs her with his weapon. She is saved just in time by a holy radiance that summons a warrior who saves her. Now, Ayaka has no choice but to enter into the Second Holy Grail War and survive.
- Ayaka Sajyou
- She is the previous protagonist of Nasu’s original Fate/Stay Night, later replaced by Shirou Emiya. She appears to be a very insecure person, traumatized after the previous Holy Grail War after her father and sister died because of it, and not willing to join the current one. On the anniversary of her father and sister's death she is pursued by Lancer much like Shirou. She is also saved at the last moment by her Servant, Saber. Her position as Master is under The Seventh, Princes.
- The First, is the previous male version of the female Saber. He responded to and accepted the summons of Ayaka in time to save her life from Lancer who had been pursuing her. He shows the sense of values of a matured man, as well as a strong sense of justice.
- The Sixth, Powers
- The Fifth, Virtues
- He is the Master of Archer. He's the owner and president of a skyscraper that overlooks the city. Little is known about him other than that he is a careful person to the end.
- The Third, is the previous version of Fate/stay night's Archer. He is the most self-centered person in the world and wishes to be the highest ranking Servant. Having two above him enraged him to the point where he wanted to kill his own Master.
- The Fourth, Dominions
- Aro Isemi
- He is the Master of Rider. He has the appearance of a 10-year-old boy, a victim of a "chimerization" experiment by the unknown antagonist of the last War. At the beginning of this War, he was entirely sustained by medical machinery.
- The Fifth, is a Servant that was to be used in the original Fate/stay night novel, but was redesigned and briefly shown in Fate/Hollow Ataraxia. He hated his Master for being weak, but sympathizes with the magus' plight, and later becomes good friends with him, prior to his death. Rider fights alone for the one wish to resurrect his Master.
- Misaya Reiroukan
- She is the previous version of Rin Tohsaka. She is a noble woman and a sadist; proud, elegant, cruel and calculative. Misaya is the Master of Lancer and the one who ordered Lancer to track down Ayaka in order to eliminate her. Misaya's position as Master is under The Second, Cherubim.
- The Fourth, is the previous version of Fate/stay night's Lancer. He acts like a normal Servant under the commands of his Master, Misaya Reiroukan. Despite having his Noble Phantasm sealed by her and her personality, he likes her, as she reminds him of his teacher.
- Sancraid Phahn
- He is the Prototype version of Kirei Kotomine. He appears as a complete maniac, switching between a kind persona and an evil psychotic one that is completely obsessed with the Grail. He's the Master of Berserker. Sancraid's position as Master is under VOID, Absence.
- The Prototype Version of Hercules
- Manaka Sajyou
- She is the previous version of Illyasviel von Einzbern. She is the older sister of Ayaka and the previous Master of Saber. Manaka is also the one responsible for the tragedy that occurred in the last War. She now acts as the Master of Beast. Her position as Master is under The First, Seraphim.
- The Beast is the Servant of Manaka, and is the 666th Beast of the The Apocalypse of John of Patmos and the manifestation of the sins and desires of men. The complete materialization of the Beast is the entire purpose of the Heaven's Feel system. It is similar in concept to that of Avenger. It is born out of the Grail being filled with the Evil, Greedy Intentions of Humanity, rather than Good Intentions.
- Hiroki Sajyou
- Voiced by Hiroki Tōchi. Hiroki is a magus and the father of Manaka and Ayaka who died during the course of the First Holy Grail War in 1991. In Fate/Prototype Fragments of Sky Silver, he shows regret at not being a better father to Ayaka and Manaka.
The original version of Fate/stay night, now called Old Fate (旧Fate, Kyū Fate?) and Fate Origin, was a novel that Nasu wrote during high school, eventually being vastly redesigned as a visual novel to suit the target audience. They were reluctant to completely abandon many of the "original charms" that were discarded, and they had wished to utilize them somehow with each passing year. Twenty years after originally being penned, they decided to make use of the release of Carnival Phantasm, discarding other proposals like Princess Arcueid VS Saber Lily or a scene from Tsukihime 2, to "just once, return to the original" for the company's belated tenth anniversary.
They decided to frame the animation like a movie trailer, utilizing the best parts and still telling the story properly. Nasu feels that the main idea of the work was in the style of an ‘80s romance, “A story of revolutionizing the world”, and took great interest in returning to the work. The large difference in obtaining the Holy Grail from the original to the final product in Fate/stay night can be said to represent the changing trends of the period.
It was originally released as a twelve-minute anime segment released with Carnival Phantasm Season 3, and included the Prototype Material databook. There are no current plans to develop the work into a full story.
An artbook titled Fate/Prototype Tribute Phantasm was released in August 2012.
Fate/Prototype has a comedy drama cd called "Fate/Prototype Drama CD" which was included with the Comptiq December 2012 issue.