Doraemon takes Nobita Nobi decades into the future to check whether he ever marries his classmate Shizuka Minamoto, but a miscalculation lands them the evening before the wedding instead of the day itself. Following adult Nobita and his old friends Gian and Suneo as they scramble to return a lost cat before morning, the short lingers on the small, ordinary night before a life-changing day rather than the ceremony itself. It expands a single 1981 manga chapter into a stand-alone story.