Having had a big quarrel with his beloved wife, Gleb Sazonov, nicknamed Bison, leaves for a seaside town and is hired as a tutor to the son of the richest woman in those places, Irma Gromova. Ten-year-old Prokhor Gromov does not go to school, has no friends, does not play around, does not misbehave. He hides in corners and often visits psychiatrists. In addition, his older sister Nastya accuses all men who appear in the house of harassment. Gleb was so lucky... However, Bison is not a timid guy. He manages to get along with both children. Everyone is shocked, Irma is delighted. But one day Prokhor is kidnapped...