Alice, a high school student navigating life during Japan's Showa era, discovers an unexpected connection with Sho when they meet in their local library—only to learn he attends school decades away in the Reiwa period. Separated by the immutable barrier of time itself, the two must grapple with an impossible romance while simultaneously uncovering that the library where their worlds collide faces an uncertain future. What begins as a chance encounter becomes entangled with a struggle to preserve the very space that brought them together.