Aki is a woman from a rural, mountainous region who appears as the central figure in the story of the Cotton Changeling. Her background is marked by profound loss and a deep, unmet desire for a family. Before the events of her encounter with Ginko, she was married to a wealthy merchant. When the son and heir she bore him died, the merchant divorced her, leaving her without a child or a place in that family. She eventually remarried a kind man who was aware of her past sorrow, and they lived together in a modest home in the mountains.

Aki’s personality is defined by a quiet desperation and a consuming love for the child she believes she has finally been given. She appears to be a devoted and protective mother, caring for her young son with all the affection she had long been denied. However, this devotion borders on a willful ignorance, as she overlooks the increasingly strange characteristics of her child, such as its green hair and unnatural growth, preferring to cherish it rather than question its nature. Underneath her maternal tenderness lies a woman haunted by grief and clinging desperately to the chance to be a mother.

Her primary motivation is the simple yet powerful desire to have and raise a child. This yearning is so strong that it blinds her to the reality of the situation. When she discovers a green, moss-like stain on her wedding gown, she does not see it as an omen but as a trivial occurrence. Even when her son begins to exhibit peculiar traits, her need to protect her family unit overrides any suspicion. Her entire identity becomes wrapped up in the role of a mother, and the preservation of that role is her driving force.

In the narrative, Aki serves as the tragic client for Ginko, the traveling Mushi expert. Her story is not one of a simple resolution but of a heartbreaking confrontation with the truth. Ginko is called by her husband, who has grown deeply concerned about their son’s bizarre nature. Through Ginko’s investigation, it is revealed that Aki’s real fetus was killed in the womb by a Mushi called a Watahaki. This Mushi then produced clones of itself that took the form of children, one of which became the boy Aki raised. When the truth is uncovered, the Mushi instinctively tries to force itself and the family into a hibernation by setting the house on fire. While everyone survives the fire, Aki is left sobbing and childless once again, kneeling in the ruins of her home. Her role is to embody the painful intersection of human love and the indifferent, often cruel, laws of the natural world that Mushi represent.

Key relationships define her existence. Her bond with her first husband ended in rejection and sorrow after the death of their son. Her second husband is a compassionate man who understands her trauma and seeks help for their family, ultimately trying to save her from the Mushi’s influence even as it destroys their life. Her most significant relationship, however, is with the child she raised, who is not human. This bond is real to her, but it is a one-sided love based on an illusion, making its inevitable severance all the more devastating. Her relationship with Ginko is that of a client who does not want his help, as she resists his investigations that threaten to shatter her happiness.

Aki experiences no personal growth or heroic development. Instead, her story is a tragic arc of descent. She begins as a hopeful mother, transitions into a fiercely protective parent who denies reality, and ends completely broken, forced to relive her greatest fear of losing a child. She does not overcome her tragedy; she is consumed by it, left to live with the ashes of her home and her hopes.

Regarding abilities, Aki possesses no supernatural or special skills. She is a normal human woman. Her physical appearance is unremarkable, described as having black eyes and black hair often tied in a ponytail, and she wears a traditional yukata. Her strengths are purely emotional, characterized by a deep, persistent capacity for love and suffering.