Ten-graders Gosha and Zosya are in love with each other. The last school waltz has been played and it seems nothing stands any longer in the way of the young people being together. However, getting the news that he's going to be a father soon, Gosha chooses a free life.

Elena Tsyplakovaas Зося Кнушевицкая
Sergei Nasibovas Гоша Кораблёв
Yevgeniya Simonovaas Дина Соловьёва
Yuriy Solominas Павел Кнушевицкий (отец Зоси, главврач)
Natalya Vilkinaas Элла Кнушевицкая (мать Зоси)
Viktor Kamaevas Владимир Соловьёв (полковник, папа Дины)
Nina Menshikovaas Соловьёва (мама Дины)
Viktor Proskurinas прораб
Sergei Bachurskyas Слава из Пушкино
Antonina Dmitrievaas директор школы
Pyotr Kataev