Although happiness was invented in America in 1962, it is still difficult to get hold of.
An energetic wife named Liisa gets an idea and interrupts her writer husband as he watches TV. Liisa suggests that he should write a book about happiness, never guessing that the subject will demand background research.
The writer sets himself the task of getting acquainted with the essence of happiness with the help of his buddy Hannu. The two men travel by cruise ship to Maarianhamina, interview a happiness researcher, a rich man, a champion runner, and a gravedigger, and acquaint themselves with physical labour and life in an ecological model community in Luhanka. Hannu applies himself particularly to the question of sexual happiness.
As their happiness research advances, the writer is finally driven to follow the tracks of his own happiness, which lead him to the days of his youth. Remembering his love for a Danish girl named Liselotte, he begins hopeful plans for a trip to Copenhagen.