Everyone knows about the love triangle. They admit that a quadrilateral is also possible - when the fate of one couple intersects with the fate of another. But it is completely atypical for children to become two corners of this quadrilateral. The friendship of two boys dramatically changes the lives of their single parents. At first, they—the father of one and the mother of the other—unwittingly get to know each other. And then everything gets confusing: the quadrangle becomes the squaring of a circle, in which situations begin to change with kaleidoscopic unpredictability.