Three university students decide, before they pursue their various careers, to spend some time together living in a mill.A young woman joins them for a while and all three fall in love with her.
According to his last will, the rich American uncle of vacuum cleaner salesman Peter Pett only leaves his 5 million dollars to Peter if he is married happily.
Herr Werther, a new magistrate to the Grand Duchy of Walheim who is a violinist and poet, seems to have fate on his side as he meets and pursues a beautiful local woman, Charlotte.
The underage Rosemarie is still too young to run her inherited farm by herself; but she's more than aware that her foster father and the farm's administrator, the farmer Schlieker, is constantly skimming from the farm's finances to line his own pocket.
Three mice run, cavort, sing and dance around in the stores and restaurants a big city at night. They wind up in a café for an early-morning snack and stocking up on food provisions before they return to the safety of their den beneath a man-hole cover in the street.