TV-Series
Description
Aya Tozawa is a young woman who lives alone in a mountain forest, where she crafts letter carriers for mushishi. She is a member of the Tozawa family, which has a long-standing tradition connected to the keeping of uro, a type of mushi. When Aya and her older sister Ito were two years old, the family elder tested them for the ability to see mushi, as was the family custom. Both sisters proved able to see the uro kept in a jar, leading the elder to declare that he would return for one of them when they turned ten years old.

In the years that followed, Aya and Ito learned to collect cocoons and harvest silk. They were also taught an important warning: they must never pick empty cocoons. When the elder returned for the girls at age ten, their parents could not decide which daughter to send. The elder decided to take the younger sister, Aya. Seeing Aya's fear, Ito immediately volunteered to go in her place. Aya, however, refused to let her sister go alone and insisted on accompanying her. The elder agreed to take both girls, believing that being together would ease their loneliness, especially since he did not expect to live much longer.

Aya initially appeared frightened upon arriving at the elder's home deep in the mountains, but she soon relaxed upon discovering that he had collected many stories to share. She became enthusiastic about learning and even helped relocate an uro into new paired cocoons, showing early courage despite her fears. She enjoyed her life with the elder and her sister, appearing happy in their shared home.

The defining tragedy of Aya's life occurred when an uro attacked them. A sheet fell over Ito, and when Aya lifted it to free her sister, the uro took Ito away. Aya blamed herself for this loss, and her grief did not ease even after the elder assured her it was not her fault. She continued to mourn for five years after Ito's disappearance and following the elder's death. During this time, she stopped wearing the colorful, patterned kimonos of her childhood, cut her hair short, and let her appearance become disheveled and exhausted. She lives alone in the mountains, still searching for her sister. She places letters into empty cocoons, hoping that her messages might somehow reach Ito.

Aya is deeply family-oriented and values the traditional crafts she learned as a child. Her defining motivation is her love for her sister, which first drove her to follow Ito into apprenticeship and later consumed her with guilt and a relentless search for closure. She struggles with self-care due to her profound grief, caring more for Ito than for herself.

Aya possesses the ability to see mushi, a rare gift that was identified in her early childhood. She is also skilled in the family's traditional craft of working with cocoons and silk. Her role in the story is as a character encountered by Ginko, a traveling mushishi who becomes concerned about her because she has been searching for her sister for five years. Ginko shows her an uro passageway, which helps lessen her mourning. Following his visit, she appears more groomed, perhaps indicating she is beginning to grieve less.