Doraemon: 2112-nen Doraemon Tanjou

Doraemon: 2112 - The Birth of Doraemon

ドラえもん 2112年ドラえもん誕生

The movie is sort of a prequel to the entire series, it showed the life of Doraemon before traveling to the 20th century: How he was made, how he was partially broken, how he lost his ears, how he met the Nobi family and decides to return to the past to help Nobita.