The main character of the series "Fool" is a lonely girl named Katerina from a small provincial town. She works as a simple hairdresser. She has no beloved man, close friends, or any special plans for life. Her colleagues call her a fool behind her back. One day, her boss Victoria jokingly gives Katerina her lottery ticket "out of the blue," along with her ex-husband who she has left behind. However, it turns out that Matvey is actually falling in love with Katya, and the ticket unexpectedly turns out to be a winning one.