Always cheerful, Serafima conflicts only with one person - neighbor Boris, who always puts the car on the playground. Boris has a hard time in his life - he gets divorced from his wife, and then the neighbor pours oil on the fire. Enmity goes so far that Sima, in a fit of anger, sets his car on fire.

The machine is destroyed. Boris is furious and demands money for damage. But the heroine has no money. Sima faces prison, and her children - an orphanage. Boris sees only one way out - to recover the child support she is owed for many years.

But it turns out that all the children of Sima are born from different men, and where these men are - no one knows. Boris has his own firm - a private detective agency. He offers Seraphima his help and goes with her in search of her exes