Doraemon is a robotic cat that lives in the 22nd century, and is known as a caretaker who helps others with his futuristic gadgets. One day he is approached by Sewashi Nobi, the great-great-grandson of Nobi Nobita. Sewashi demands of Doraemon to go back to the past and make Nobita happy in order to prevent a disastrous and bleak future. Doraemon is not excited about this idea, but Sewashi installs a program into Doraemon and eventually sends him back to the past.

Nobita Nobi is an elementary school boy who is very lazy, unlucky and a scaredy-cat. He gets bullied by everyone and does not excel in any school subject. When he meets Doraemon for the first time, the two of them start off on the wrong foot; however, they soon become great friends. Doraemon cannot go home to the 22nd century unless he turns Nobita into a boy who can stand on his own and be happy.