The boyish, temperamental chemistry student Elsa Kassel disapproves of her mother and sisters running after men, but when she hears that she's referred to as "ugly Elsa", she takes on a transformation. The new, charming Elsa tests her attractiveness on men and causes confusion all the way to her mother's new groom, Professor Harjula.
In the remote village of Hurula, the mistress of the house has forbidden her henpecked husband from enjoying himself and playing the accordion. The ceremonious host Ernesti courts the Hurulas' daughter Pirkko to be his wife. However, she falls in love with the village's new cantor Pelle, but multiple misunderstandings have completely complicated matters.
The new idealistic welfare officer Helmi tries to improve conditions in "Sin Alley," but difficulties arise, particularly with the leader of the petty criminals, Jukka, whose son Reino also drifts into a life of crime.
