Nobita coaxes his friends to join him for a treasure hunt but an eerie event transports them to the past. However, their hunt for treasure is not easy as they come face-to-face with pirates.

Nobita was reading a picture book.In that he sees Adam and Eve disobeying god and eating the apple in the garden of Eden. Nobita comments that their descendants have to face many difficulties because of Adam and Eve's mistake. Then Doraemon reminds Nobita that he had to do his summer vacation research homework.

Nobita Nobi is so hapless that his 22nd century decendants are still impoverished as a result of his 20th century bumbling. In a bid to raise their social status, their servant, a robotic cat named Doraemon, decides to travel back in time and guide Nobita on the proper path to fortune. Unfortunately Doraemon, a dysfunctional robot that the familly acquired by accident (but chose to keep nonetheless), isn't much better off than Nobita. The robot leads Nobita on many adventures, and while Nobita's life certainly is more exciting with the robot cat from the future, it is questionable if it is in fact better in the way that Doraemon planned.