Upon hearing about the story of Treasure Island, Nobita dreams of discovering and exploring his own treasure island, despite the fact all of the Earth has been mapped already.

The students of class 3-E have a mission: kill their teacher before graduation. He has already destroyed the moon, and has promised to destroy the Earth if he can not be killed within a year. But how can this class of misfits kill a tentacled monster, capable of reaching Mach 20 speed, who may be the best teacher any of them have ever had?

Fourth-grader Nobita Nobi tries to improve his present life so that his loyal cat robot, Doraemon, can return to his home in the future.

Nobita and Doraemon use time tree Mochi and catches a big bird Moa, which has been extinct for 500 years ago. To protect extinct the animal, Nobita and Doramon go to Beremon Island which is protected by a golden beetle named Herakles. They meet a girl from the Rokkoro tribe and a boy who looks exactly like Nobita on Beremon Island ...