Deep Sea Cycling

Suneo shows off to Nobita and Gian about his camp on a private island. But he denies Nobita from visiting it, infuriating him. Nobita asks Doraemon for help, and he replies that not knowing how to cycle is Nobita's own fault. Nobita asks Doraemon for something to help him learn cycling quickly, so Doraemon brings out the Underwater Bicycle. Nobita immediately climbs on it but falls down, as Doraemon explains it only works properly underwater. They go to the river and start practising. Nobita easily rides around for some time in the water.

Shizuka calls on from the bridge above, and they decide to visit Suneo's island together the next day. The next morning when Doraemon, Nobita and Shizuka are ready to leave, they ride with the backpacks through the river. Slowly, they reach the sea port where two scuba divers fixing a pipe call Doraemon a raccoon; Doraemon shouts back. They reach the end of the continental shelf, after which they face a steep slope. A large whale swims nearby them. Nobita overspeeds during the cycle and falls off his bicycle after reaching the bottom. He holds a tentacle-like thing in his palm which slides away. Doraemon and Shizuka arrive and merely convince Nobita that it was the underwater cable that transfers internet and call data.

Many twilight-zone fish are seen swimming around. They set up a campfire underwater and have seafood as snacks. Nobita asks what the fish is, while a huge squid, whom the tentacle held by Nobita belongs to, comes down behind Nobita. They try to escape by putting their bicycles at full gears but Nobita is unable to speed up, is caught by the squid. Just then, the whale that swam close to them before arrives and bites the squid, dragging it down through a crack in the ocean floor. They finally reach the island where Suneo is, and Doraemon activates balloons on the bicycle which drags them up. Gian and Suneo are cycling on the port discussing how "Nobita missed all of this", but Nobita, Doraemon and Shizuka rise from the sea, bragging back at them telling "how much they missed". They get up a drag slope at the port and Nobita, unable to control his cycle, falls down again as Doraemon wonders when Nobita will learn how to ride a bicycle.