The term "Czech harem" might be considered an oxymoron, as harems are typically associated with Eastern cultures. However, there are reports of modern Czech men engaging in relationships with multiple women, often in an unconventional, non-polygamous arrangement. These relationships may involve a dominant male figure and multiple female partners who engage in consensual, often romantic and intimate relationships.
Given the context, I'll assume you're referring to a specific type of anime, manga, or a fantasy setting that combines elements of Czech culture with the concept of a harem. Without a specific title or more context, I'll provide a general review of what one might expect from such a theme.