Nao Sumida is a supporting character in the horror manga Sayuri by Rensuke Oshikiri and its live-action film adaptation. She is a classmate of the protagonist, Norio Kamiki, and is among the first to sense that something is deeply wrong with his family’s new home.

Nao is portrayed as a quiet and reserved girl who possesses a natural sensitivity to supernatural presences. From the moment she becomes aware of the Kamiki house, she is visibly unsettled by it, and her intuition tells her that the building harbors a dangerous entity. Despite her own fear, she is deeply concerned for Norio’s safety and does not hesitate to warn him about the danger he and his family are walking into. Her concern is not casual; it is persistent and earnest, revealing a loyal and caring nature beneath her shy exterior.

As the story progresses, Nao’s motivation shifts from simple worry to active determination. She repeatedly checks on Norio and tries to persuade him to leave the house or at least take the threat seriously. When the situation becomes dire, she overcomes her own terror to physically enter the haunted building in an attempt to help him. This marks a significant point in her development: the ordinarily discreet girl is willing to confront a malevolent spirit for the sake of a friend. Her actions show that her quiet demeanor masks a genuine courage that surfaces when someone she cares about is in peril.

Nao’s key relationship in the story is with Norio. There is an unspoken affection between them, and her protectiveness toward him goes beyond ordinary friendship. She is his anchor to the outside world and a source of emotional support, even when he is too overwhelmed to appreciate it. She also interacts briefly with Norio’s grandmother, Harue, whose own fierce determination to fight the spirit parallels Nao’s quiet bravery. Nao’s ability to sense and perceive the presence of the ghost is her most notable ability, and it is what sets her apart from the other characters; she can feel the malice of the house before anyone else fully comprehends it.

Over the course of the story, Nao is transformed from a background classmate into an active participant in the struggle against the haunting. She is one of the few characters who survive the ordeal, and after the spirit is laid to rest, she returns to her normal life, having proven herself to be far braver than her initial demeanor suggested.