Doraemon went missing for 3 days. But it turns out later that he went to the 22nd century to buy a mystery galactic express train ticket whose destination is a secret until the passengers arrive there and see for themselves.
Doraemon: Nobita and the Galaxy Super-Express , also known as Doraemon and the Galaxy Express, is a 1996 Japanese animated science fiction neo-Western film and the 17th feature-length Doraemon film. It premiered in Japan on March 3rd, 1996, based on the 16th volume of the same name in the Doraemon Long Stories manga series.