In the serene countryside of 1940s Japan, a young narrator passes the long summer days in a hidden fort, far from the single daily bus that connects their rural world to the outside. Childhood routines unfold amid simple pleasures until an unexpected rainstorm arrives, forcing a dash for shelter. At the lonely bus stop in the downpour, a chance meeting introduces a new presence that hints at fresh discoveries ahead. This first encounter sets the tone for an idyllic season of exploration and quiet connection.