Tooi Umi kara Kita Coo

Kouichi Uehara is a fourth grade student living in the suburb of Tokyo. One day, he picks up a large stone which turns out to be a fossil of a baby "Kappa" sleeping underground for the past 300 years, and names it "Coo". Koichi and Coo become good friends and starts living with his family. However, Coo could not adjust to the life style in Tokyo and starts to miss his family. On a hot summer day, Koichi and Coo decide to go on an adventurous road trip to find his peers.

Jun, his female companion, Remi, and her little brother, Chobi, are taken to the Cretaceous Period by a flying saucer.

Uiba Shikatani, the daughter of a pet shop owner is heartbroken after some reptile eggs fail to hatch. In his attempts to cheer her up, her father brings home a large, striped egg, which he hopes will successfully hatch (unexpectedly into a green dinosaur whom they call 'Muka-Muka', which are the only words which the baby reptile can speak). Muka-Muka soon becomes the talk of the town and comes into the interest of the town's professor and his wacky inventions, including a time machine which successfully teleports the Shikatani's among other families and their homes to pre-historic times where they encounter several other dinosaurs and enchanted beings on their adventures.

Nobita finds a fossilized dinosaur egg by accident, and with the help of Doraemon's tools, they hatched the egg and began raising the dinosaur. Knowing that they can't keep the dinosaur forever, Nobita was forced to send it back to prehistoric times where a group of hunters from the future threatens to endanger the dinosaurs. Determined to save the dinosaurs from the claws of the hunters, Doraemon and the gang returns to the past and sets out in a prehistoric adventure.