The young people, yesterday's schoolchildren, who live in Leningrad, enter adult life. Sonia loves Styopa, but he loves Tania who prefers Fedia. The rejected Styopa leaves Leningrad to live in a remote Siberian town where he works in the factory and attends lectures in the evening institute. Sonia goes after him and finds a job in the same factory. After getting married Tania and Fedia enter the institute, but the young husband in order to support his family has also to work as driver. Tania’s egoistic nature refuses to put up with the modest situation the newlyweds has to live in, and makes love with an aged composer.