Four ducklings are already swimming in the pond within a few days of hatching. Their mother is sitting on the last and largest egg. The grandmother duck, who likes to chat, worries that it may be a turkey egg. The chick that hatches three days later has a long neck and quacks in an unfamiliar way. However, the mother duck is relieved to see the youngest duckling actively training to swim. Being different from other ducklings in appearance, he is mocked by dogs and bullied by frogs. He is despised by other ducks and ostracized by his four brothers. One evening, the youngest duckling leaves his mother and brothers. In autumn, the duckling who continues to travel alone asks a goose to let him join his flock. While they are talking, they see a hunter fire a gun and barely escape the hound. Autumn gives way to winter. The duckling is lying on a bed in a cabin near a second house on the lakeside. A black cat and a hen are watching the duckling with a concerned look. The duckling wakes up and is told by the black cat that he was saved while being attacked by a weasel. The hen says that the duckling does not look like a duck, and the black cat tells the duckling that he can stay as long as he wishes. Summer comes after the spring. Children in a second house spot a beautiful swan. The black cat tells the hen that he is proud of having raised the swan. The young swan's days are peaceful and happy. When the evening comes, the swan remembers his gentle mother duck.

(Source: Japanese Animated Film Classics)