Keiyaku Shimai

Kasane Hayafuji navigates her days with a quiet, unassuming rhythm, but she harbors a small, secret treasure that brightens every monotonous hour: the sight of Aoyama-san, a gentle waitress who works at the family restaurant Kasane frequents. Their interactions are fleeting—a polite greeting, a refill of coffee, a murmured thank you—yet these modest exchanges have become the emotional anchor of Kasane's life, a private joy she guards closely. She never expects that this simple, almost ritualistic admiration will be the catalyst for a profound and startling turn of events. One evening, as a cold rain descends upon the city, Kasane happens upon a scene that stops her heart. There, standing solitary beneath the downpour, is Aoyama-san, her uniform soaked through, her expression betraying a sorrow that cuts through the storm. Concern overrides Kasane's hesitation, and she rushes forward, intending only to offer an umbrella or a comforting word. But before she can formulate her help, Aoyama turns to her with eyes full of desperation and makes an unexpected, life-altering proposition. "Will you be my big sister?" The request is simple in phrasing but immense in implication—a plea that dissolves the safe distance between customer and server, demanding that Kasane step into a role fraught with unfamiliar responsibility and emotional turmoil. In that rain-soaked moment, Kasane realizes that her quiet crush has evolved into a tangled, complicated bond that will challenge her understanding of family, duty, and the true nature of her feelings for the woman before her.