Ostap spends the summer with his grandmother in the country. There he has everything that makes a perfect vacation: cool Ba, fun weekends with dad, best friend Les and constant adventures. And somehow a cat comes to the yard. Ostap calls him Nechuev - for his stubborn desire not to hear others. After learning from his grandmother that cats have nine lives, the boy decides to keep an eye on Nechuy's lives to test this theory.