The story revolves around a modest and sweet girl named Marina, who is nicknamed "Mouse" behind her back due to her plainness and shyness. The main heroine is studying at the conservatory. With the help of her mother, the legendary actress Inga Belozerova, she started studying with the best teacher, Nina Georgievna. Soon, Marina falls in love with Nina's son, Kirill, and the young couple begins a romantic relationship. However, first love is never without its complications...