At Okagi Castle, Yuuki tells his childhood friend An that his family will be relocating. Promising to return once he grows older, Yuuki admits he'd like them to go out together then. Uncertain whether their feelings will stay the same when they meet again, An flees in panic and stumbles upon a portal at the castle"s entrance. Crossing it, she finds herself fifty years ahead, where neon lights glow over a skyline that now includes the castle beside towering skyscrapers.
Confused, An is met by a boy named Kibou and his amiable robot Butler‑kun. By chance, Kibou"s grandmother has instructed him to help any distressed girls he meets at the park, so he offers to escort her and keep her safe. While the trio wanders the city—visiting a bustling market, strolling through a quiet park where old cherry trees still sway—they notice that although Okagi has transformed, its old‑world charm remains intact in the nostalgic streets.
