Herz - modern möbliert follows a chaotic web of romantic and real-estate misunderstandings when a theatre technician named Hans buys a small apartment for his upcoming marriage to a glamorous showgirl named Daisy. Coincidentally, a wealthy admirer buys Daisy a second, much larger apartment as a gift to win her over. Daisy and Hans hire the exact same interior designer, Lore, to furnish both properties, which lets Lore discover the messy double-dealing taking place. Comedic chaos peaks when the wealthy admirer suddenly drops his pursuit of Daisy and tries to win over Lore instead.