Belgium is, as described by Humon, a "geek with a sweet tooth". He has reddish-brown hair and freckles and wears shiny glasses that obscure his eyes. He enjoys reading comics, as Belgium is well-known for its comic industry. He once participated in one of Greece's drunken parties.
He is shipped with Netherlands by Sister Japan, who revealed in Kindred Spirits that she was working on a manga about them. Netherlands disapproved of this pairing and complained about being paired with a geek.