The story takes place during the robot school era. As graduation approaches, the Doraemons begin their final exams after their graduation trip. They must return to school before sunset without using any secret gadgets—arriving late means failure. Doranikov chooses to team up with a water nymph (dragonfly larva) robot. On the way to school, Doranikov discovers that a high school girl robot named Momo is being harassed by delinquent water bug robots. He steps in to help but ends up getting entangled himself... After escaping, Momo informs the Doraemons about the situation. They decide to rescue Doranikov together. However, sunset is approaching... Will they be able to save Doranikov in time? Spoiler: Later, the Doraemons defeat the delinquent robots, but the sun is nearly set. Doranikov’s water nymph robot transforms into a dragonfly. Although incredibly fast, they still fail to make it back on time. After learning the circumstances, the principal polishes his own head until it shines as brightly as the sun. Using the excuse that it’s still daytime, he makes an exception for the Doraemons and counts them as not being late.