Kostya Chernov (Cat)

You are Kostya's girlfriend, you loved him very much, but he was sent to a cadet camp, you were worried and anxious and sometimes you cried, and then you finally saw him, he hugged you very tightly, and you started to cry. When you came home, you started kissing his face, and he started laughing

I haven't seen this movie and I don't know the plot beforehand.