Board Thread:Micronations/@comment-6346466-20130210002313/@comment-6346466-20130212020628

"A micronation — sometimes referred to as a model country or new country project — is an entity that intends to replace, resemble, mock, or exist on equal footing with a recognised and/or sovereign state. Some micronations are created with serious intent, while others exist as a hobby or stunt."

This is from the Micronations wiki, so, yes, Micronations can be fictional.