Aya Watsuji is a central figure in the visual novel and anime Interlude, distinguished as a skilled archer and a young woman grappling with a profound disconnection from the world around her. Her existence is marked by a deep and pervasive loneliness, as she lives alone in a town that is mysteriously devoid of other people. To cope with this unsettling emptiness, Aya adheres to a strict, self-imposed routine, continuing to live as if everything were normal. She faithfully catches the train to school each day and studies alone, operating under the fragile hope that by pretending nothing has changed, the missing population will eventually return. This careful performance of everyday life masks a mind under tremendous strain, leading to descriptions of her as a girl who is slowly going insane.

In the story, Aya acts as a crucial guide and protector for the protagonist, Naoya Aizawa. When Naoya finds himself trapped in the strange, deserted Moon City and is attacked by shadowy creatures known as fairies, it is Aya who rescues him using her bow and arrows. She takes him to her home, revealing that before she saw him on a railway platform in a recurring dream, she had encountered no other living soul in her world. This meeting marks the beginning of a deep and pivotal relationship, as Naoya becomes the first person to break through her isolation. He encourages her to break her solitary patterns, such as accompanying her to an amusement park, and in turn, she becomes the key to understanding the nature of the fractured reality they inhabit.

Throughout the narrative, Aya evolves from a passive figure clinging to a semblance of normalcy into an active agent of change. Initially resigned to her lonely existence, she begins to risk herself and fight for a future beyond the illusion. Her emotional development is closely tied to her connection with Naoya, as she rediscovers a taste for life and human connection. Ultimately, her role transcends that of a mere survivor; she is revealed to possess the unique and dangerous ability to shatter the false reality that has been constructed. In a climactic moment, she fires an arrow that destroys a manifestation of the illusion, demonstrating her resolve to face an unknown but genuine future rather than live in a comforting but hollow past. Her notable ability is her exceptional skill with a bow, which she wields effectively against the shadowy creatures that threaten her and Naoya, making her not only a tragic figure but also a formidable protector and the story’s primary instrument of liberation.