Set in the early 1960s, the story evolves around highschool sweethearts Jonas and Agnete, their friendships and families, trials and tribulations. Jonas fails to give Agnete the kind of attention she craves, and when she decides to start a new romance, he feels for the first time a cold stab of jealousy. Their rocky relationship takes Jonas through the spectrum of emotions that arises with an aching heart. »Aching Hearts« is shot over a period of three years, taking into account the development of the young actors, some of whom are amateurs from the actual milieus Malmros is depicting.
