The moral is radical for a children's film: The thing you are bullied for in school might be the thing that saves the world.
If you are new to the franchise, these three "Nobita Movies" are considered masterpieces of Japanese animation: nobita movie
Once there, the gadgets fail. Doraemon’s "Bamboo Copter" might run out of battery, or his "Small Light" might break. Nobita is stripped of his safety net. Suddenly, the boy who relies on magic tools must rely on his own hands. The moral is radical for a children's film:
If you want to start watching, these are considered the masterpieces of the franchise: nobita movie