"-kun" is not at all male only. It is often used to refer (respectfully) to people of lower status. Dragon boy is the president and Ogami and Yumenaka are below him in the council. "-kun" may also imply familiarity as part of the same group in a professional setting (the council). Using "-chan"...
In terms of countries, there is Austria, Central African Republic, South Africa, South Sudan, Timor Leste, North Macedonia, what we have contemporarily. So it's not like there are no countries named like that.