The story takes place in the 1950s. Konstantin “Kostik” Romin (Oleg Menshikov) has come to Moscow to study history and is staying with kindly aunt Alisa (Sofya Pilyavskaya), who runs a communal apartment building there...展开. His life soon becomes intertwined with those of the other residents. Among them are Margarita Pavlovna (Inna Ulyanova) and both her former husband Lev Khobotov (Anatoly Ravikovich), a publisher of foreign poetry, and her new beau, engraver-turned-teacher Savva Ignatevich (Viktor Bortsov).
The main plot revolves around the congenial Khobotov’s attempts to find happiness with newfound love Lyudochka (Yelena Koreneva), while constantly being thwarted by the controlling Margarita. Another tenant is musical comedian Arkady Velyurov (Leonid Bronevoy), who is trying to revive his faltering career and escape from his own loneliness. He has become enamored of a young competitive swimmer, Svetlana (Tatyana Dogileva), who rebuffs his advances but takes a fancy to the opportunistic Kostik.
Kostik finds his own love interest, Rita (Valentina Voilkova), for whom he decides to forsake his playboy lifestyle. In the end he becomes the catalyst for both Khobotov and Velyurov to find some measure of happiness: the former elopes with Lyudochka with the help of Kostik's pal Savransky, and the latter is elated that Svetlana attends one of his concerts in response to a telegram Kostik had urged him to send.