The Narrator in "Eiga Sumikko Gurashi: Tsugihagi Kōjo no Fushigi na Ko" fulfills the consistent narrative role established across the franchise. This character lacks a personal background story or development arc, serving a primarily expository and emotional function rather than a character-driven one.

The Narrator interprets the non-verbal actions and internal states of the silent Sumikko Gurashi characters. This includes conveying Shirokuma's sewing machine proficiency and Penguin?'s meticulous toy inspections during their discovery of an abandoned factory. The narration bridges the characters' silent interactions with the audience, emphasizing their comfort-seeking behaviors and subtle emotional shifts.

Across the franchise, the Narrator provides continuity for the characters' adventures, such as their camping trip under a blue moon in the second film or exploration of a pop-up book in the first film. In the third film, the narration elucidates themes of work and loss within the toy factory setting while preserving the characters' intrinsic need for corners and companionship.

The Narrator occasionally reflects personal identification with character traits, like expressing affinity for Shirokuma's anxiety and use of a furoshiki cloth for comfort. These reflections deepen audience understanding of the characters, not the Narrator as an independent entity. Collaboration between multiple narrators occurs in some installments, including the third film, without altering the fundamental narrative role.

No evolution or personal history for the Narrator is documented. The role remains focused on facilitating the silent protagonists' stories across films and the 2023 TV anime special, avoiding meta-commentary or subjective interjections.