Hakuno Kishinami

The main character of Fate/Extra, referred to as "Yourself", can either be male or female, and is the Master of Saber, Archer, or Caster.

Role
The protagonist begins as a student at Tsukimihara Academy and friend of Matou Shinji. However, he/she percieves something strange about the school, and winds up as a participant of the Holy Grail War after entering SERAPH and being saved by Saber, Archer, or Caster. Unlike the other participants, the protagonist does not regain his/her real memory once the war begins, and has no recollection of his/her true identity or reason for joining the war. With no wish to make, the protagonist fights only to survive. He/she uses command spells to rescue either Tohsaka Rin or Rani VIII, who becomes a close friend and ally. After defeating all opponents, the protagonist becomes the victor of the Holy Grail War.

In the game's climax, the protagonist, along with their Servant and friend, reach the core of the Moon Cell and meet Twice H. Pieceman, who tries to convince the protagonist to use the Moon Cell to wish for the advancement of the human race through war. The protagonist refuses and defeats Pieceman's Servant Saver, killing Pieceman. Upon entering the Moon Cell with his/her Servant, the protagonist is recognized as "invalid data", but is able to use the Moon Cell to learn the truth about his/her true identity and send this information to Rin/Rani before being deleted.

Past
In reality, the protagonist is not a human participant of the Grail War, but an NPC created by the Moon Cell, based off an existing person. The protagonist's "other self" in the year 2000 was a patient with a brain disease that caused memory loss and would eventually lead to death. A doctor who could potentially cure the disease was found, but died in a terrorist attack before an operation could be performed. (It is hinted that this doctor was Twice H. Pieceman.) It was decided that the patient would be cryogenically frozen until treatment became possible. Because of the world's technological stagnation, no progress was made, and he/she remained in this state for 30 years. After entering the Moon Cell, the protagonist sends Rin/Rani this information, in the hopes that she will be able to find and help his/her other self.

After being created in SERAPH as an NPC, the protagonist, like Pieceman, somehow gained self-awareness. Unlike Pieceman, he/she did not regain any memory of a "previous life" due to the fact that the original was an amnesiac to begin with. Believing him/herself to be a normal human, the protagonist unknowingly took over the position of another participant who had died in the preliminary selection for the war. As an NPC rather than a human, the protagonist cannot enter the Moon Cell without being deleted as invalid data, like Pieceman - however, the Moon Cell requires more time to process the contradiction caused by the existence of the frozen body in the real world, and so he/she is not instantly deleted and has enough time to make a wish.