Noby borrows Doraemon's time capsule for himself and his friends to bury their stuff in for twenty years, unaware that the capsule will send its contents on a 100–year trip through time. After retrieving the capsule 100 years into the past, Noby unknowingly causes another predicament that could alter Doraemon's own timeline leading Doraemon and Noby to travel to the future, to the day Doraemon was born.
