The TV series "Mezalliance" tells the story of an ordinary, easy-going Muscovite named Kostya, who was raised like a hothouse plant. All of his life decisions are made for him by his aunt, Alla Danilovna. Worried about her nephew's future, Alla Danilovna tries to find him a good wife. According to her, Kostya's long-time love interest is not at all suitable for marriage, so she invites the charming daughter of a colleague to live with them, but she turns out to be completely different than expected...