Ayaka Sajyou is a central character in the narrative of Fate/strange Fake, serving as the Master of the True Saber, Richard the Lionheart. Her background is rooted in the city of Fuyuki, though she is a distinct individual from the similarly named character appearing in other Fate works. She originally had black hair but later dyes it blonde, and she is known by the alias Person A, a reference to a ghost story or urban legend stemming from her past. This legend involves a young girl in a red hood who was the victim of domestic abuse and whose fate became the subject of a haunting tale. Ayaka is intrinsically linked to this story, as she is tormented by the persistent vision or spiritual presence of this Little Red Riding Hood, a manifestation of past trauma that follows her wherever she goes.

In terms of personality, Ayaka is defined by a deep-seated desire to live an ordinary, peaceful life, free from the influence of magic and conflict. She is a natural introvert, cautious of others and protective of her personal space, which she prefers to be a solid and impenetrable fortress against the outside world. This stems from a history of feeling powerless and betrayed. Her motivations are fundamentally shaped by a refusal to be a pawn. She is not driven by a wish for the Holy Grail but rather by a desperate need to escape the fate that has been forced upon her. This leads to a stubborn and often fearful demeanor, as she finds herself thrust into a world she does not understand and never wanted to be part of.

Ayaka's role in the story is that of an unwilling participant. She is granted five Command Spells by a mysterious woman, which forcibly connects her to the Holy Grail War in Snowfield. While being held captive by a magus named Cashura, who intended to use a catalyst to summon a Servant and have it kill her, the summoning goes awry. Instead of the expected King Arthur, the ritual produces Richard the Lionheart, and the nascent magical connection latches onto Ayaka, making her his de facto Master. Despite her vehement rejection of this role and refusal to form a formal contract, the bond persists, allowing Saber to draw magical energy from her.

A key relationship is with her Servant, Richard the Lionheart. Unlike traditional Master-Servant dynamics, theirs begins with Ayaka’s outright refusal. Richard, however, is a chivalrous and understanding king. Rather than forcing her compliance, he chooses to protect her anyway, recognizing her situation is not of her making. This dynamic is central to her development, as his unwavering support and belief in her slowly force her to confront her own self-loathing and feelings of worthlessness. Another significant relationship is with the specter of Little Red Riding Hood, a hallucination or spirit that represents her deep psychological scars. This entity is not merely a figment of her imagination but a supernatural presence tied to her origins, and confronting it is a crucial part of her journey.

Throughout the story, Ayaka undergoes considerable development. She transitions from a passive victim, who runs from her problems and denies any agency, to someone who begins to accept her situation and her own value. Her initial instinct is to push others away, especially Saber, whom she warns she will eventually betray. However, through shared danger and Richard's persistent kindness, she starts to care for his well-being, even yelling at him for recklessly protecting her. Her journey is one of self-discovery, as she begins to question her own identity and the nature of the trauma that haunts her, moving from a state of fear and denial toward a tentative acceptance of her role and her own hidden strengths.

Regarding notable abilities, Ayaka is an anomaly. She is not a trained magus and possesses almost no knowledge of magecraft or the Holy Grail War. Her primary ability is not a skill she wields but an inherent trait: she possesses an enormous and seemingly inexhaustible reserve of magical energy. This is demonstrated when her Servant, Richard, is able to unleash his Noble Phantasm, a replica of Excalibur, multiple times without draining her, a feat that would exhaust even a first-rate magus. It is later implied that this is because her very nature is that of a massive magical energy source. She also bears five Command Spells, which are distributed across her hands, shoulders, and back, granting her significant, if reluctant, authority over her Servant. Her true identity is eventually revealed to be far from human; she is the personification of a magical core, a remnant of a powerful mystic code from a previous Holy Grail War, which explains her immense power and her connection to the ghost story of the Little Red Riding Hood.