Somewhere in Europe by a great sea stands a small village, where inventing all manner of domestic gadgets is held in great esteem. Every year the villagers organize an annual competition of new inventions. One of the best inventors in the village is Oskar, Lotte's father. His primary rival is Adalbert, whose wife also partakes in the competition. On the eve of the next competition, Lotte and her friend Bruno find a book soaked in the sea, from which Susumu, a gardener from distant Japan, climbs out. Susumu teaches the villagers some judo throws before a big judo competition, which the latter will eagerly use to facilitate their daily lives.

Plucky young Lotte embarks on an adventure with her uncle Klaus to solve the mystery of three stones that a pair of hooded figures are attempting to retrieve.

Lotte gets a little sister named Roosi. Two scientists Karl and Viktor come to Gadgetville, they are taking part in a big folk song collecting competition. Whoever succeeds in recording the folk song of the world’s oldest animal species, wins the competition’s grand prize. Lotte and Roosi decide to help the scientists. Exciting and unexpected adventures await the sisters.

Little bird Pippo fell behind the flock of birds. Lotte decides to go after a flock to take Pippo to relatives. Together with her dad Oscar, inventor, who has just invented a flying machine, and old traveler Klaus.