"Kanojo no Hitori Gurashi" centers on the life of a young woman named Yui, who lives alone in a small apartment. The narrative explores her daily routines, personal struggles, and the quiet moments that define her solitary existence. Yui’s life is marked by a sense of loneliness and introspection, as she navigates the challenges of adulthood, work, and relationships. The story delves into her interactions with a small circle of acquaintances, including her coworker Haruka, who occasionally offers support and companionship, and her neighbor, an elderly woman who provides subtle wisdom and perspective.

The manga portrays Yui’s internal conflicts and her gradual journey toward self-acceptance. Her past is revealed in fragments, shedding light on the events that shaped her current state of isolation. Themes of mental health, societal expectations, and the search for meaning are woven into the narrative, as Yui confronts her fears and begins to open herself up to the possibility of connection. The pacing is deliberate, emphasizing the quiet, often mundane aspects of her life, which are contrasted with moments of emotional intensity.

The artwork complements the story’s tone, with detailed depictions of Yui’s surroundings and subtle expressions that convey her inner turmoil. The series avoids melodrama, instead focusing on the authenticity of Yui’s experiences and the small, incremental changes in her life. Through its exploration of solitude and human resilience, "Kanojo no Hitori Gurashi" offers a poignant and relatable portrayal of one woman’s journey toward understanding herself and her place in the world.