The director of the Vaudeville Theater is looking for new performers after the former star was forced to give up her singing career. Out of numerous auditionees, singer P. Waltteri Vitikka is hired. At the same time, the janitor tries to maintain order in the theater.

Composer and program director Harri forms a quartet, recruiting Apon, Teika, Kauko, and Olli as members. Based on an idea from Olli's beloved Raija, the ensemble is named the Kipparikvartetti.

Journalist Sanni visits the countryside to write about the timber industry. Looking for a room she is immediately thrust into the merry community of loggers, always up for a song, but one of them, Hurma-Jussi, is a little too persistent. Luckily, she is “saved” by the handsome lumberjack Eräs.

Ilona, an orphan from the cruel Paksula family, ends up in Helsinki at a children's home for immigrants and from there becomes a foster daughter in the Orpana family, where she begins to sort out the relationship between her war-disabled stepbrother Pentti and his girlfriend Irene.

Pekka Puupää and Pätkä, who return to Helsinki from an unsuccessful variety show tour, are forced into refresher training, where they are trained as frogmen. During the diving exercises, the friends encounter the mermaid Helmi, whom they help into the bathtub at home, to Justiina's shock. The friends, who have become civilians, eventually end up on a plane bound for Suez, being cornered by UN soldiers.

Captain Routa has to teach a civil defense class to the girls at a boarding school. He accidentally wanders into the shower room and tries to get out disguised as a cleaner, but ends up in the same bed as gymnastics teacher Marjatta. Private Pöntinen, who is dating the boarding school cook, has a blast when he gets his hands on Captain Routa's uniform.

Olli Suominen has been appointed acting sheriff in the countryside, and the whole family has left for Kesäranta to spend the summer. The peaceful rural life is interrupted when small farmer Pullin's hay barn is destroyed in a fire and Anita and Aarne, the Lokka family who have moved in next door, get to know the Suominen family.

Sten Lehtoja, a married, middle-aged businessman, picks up a young hitchhiker, Elsie, while driving to his summer home. Elsie spends the night and becomes his mistress. Later during the summer, Elsie also begins an affair with Reino, the teenage son of a local storekeeper. Sten offers to divorce his wife, and Elsie, attracted by the prospect of a secure social position, agrees to marry him when the divorce becomes final. One night when the couple are in bed, Reino climbs a ladder and attempts to force his way into their room; he falls and breaks his neck, and to avoid scandal Sten hides the body. But the strain of guilt ruins the romance, and Elsie contacts the police, who arrest her lover.

Justiina pushes Pekka and Pätkä to take painting lessons after realizing that art can be a way to earn a living. With the help of the yard children, a painting is created that wins first prize at a contemporary art exhibition. In the meantime, the men, along with their assistant Miss Kaihokielo, have been charged with art theft. After the misunderstanding is cleared up, the Puupääs use the art prize money to convert the house's bomb shelter into a children's clubroom.

A closed room mystery begins when an infamous tycoon is found dead in his bath tub. The famous police lieutenant Palmu is summoned to investigate.