Akira Kurosawa's movies have a whole range of themes, be they set in contemporary or in historical eras. To name a few: the chasm between the rich and the poor, between the strong and the weak, between the courageous and the cowards, between the powerful and their foot folk, between the honest and the deceitful, between the clever and the idiots, between the sincere and the dishonest, and also, importantly, between war (destruction and loss) and peace (happiness).
In this movie, made just after WW II, he depicts the struggle for life of 'poor lovers', whose dreams were shattered by the war. Japan is in dire straits: no jobs, and, if you have a job, bad salaries; high rents for decent shelters and huge inflation. 'Free markets' are controlled by 'black' merchants and their thugs. There is still an upper class, which looks with contempt on those without money, their former foot folk. The girl remains optimistic, but her lover is deeply depressed.
Akira Kurosawa made some very risky shots on the music of F. Schubert's unfinished symphony. But, he had the mastery to create the perfect mood. Not to be missed and certainly not by A. Kurosawa fans.