In a small, traditional bonsai shop, an android girl named Kanna learns the ancient art of caring for miniature trees from her human teacher. The full title of the story reflects its central, poignant premise: while a human life lasts at most one hundred years, as a machine, Kanna can live for a thousand. For a long, formative period, she studies under the master's patient guidance, absorbing not just the techniques of bonsai cultivation but the philosophy of patience, care, and respect for life that defines the craft.

As the years inevitably pass, the teacher is gone, and Kanna finds herself alone, the sole guardian of the shop and its precious bonsai plants. She continues her solitary work, a fixed point in a changing world, faithfully preserving the legacy she was entrusted with. The story’s quiet rhythm is broken by the arrival of a new visitor at the shop. This encounter sets the stage for the manga's final narrative arc, which explores themes of legacy, the connection between generations, and the transition of purpose. The visitor's appearance initiates a cycle of closure, bringing a blend of melancholy and gentle hope as Kanna's long vigil finally leads to a new form of connection. The narrative focuses on the emotional resonance of this relationship, contrasting the ephemeral nature of a human lifespan with Kanna's enduring, almost eternal, existence as she continues to live alone in that place, caring for the living art her teacher left behind.