Sajyou Ayaka (沙条綾香, ?) is the Master of Saver in Fate/prototype. She is the archetype version of Emiya Shirou who was to be the protagonist of the original Fate/stay night novel that was never finished. She was originally detailed in Character Material, and she has been given an expanded role in Prototype. She is one of the Seven Masters in the Holy Grail War.
Fate/strange fake
An alternate version of her appears in the official ongoing novel series as one of the main characters. She is taking over the role of the "Player" character from the original "Fate/strange fake" which originated from an April Fool's joke.
She is the "True Master" of Saber in the True and False Holy Grail Wars.
It is revealed that this Ayaka is Person A, a mysterious character mentioned in [Fate/hollow ataraxia].