You are all wrong.
Ero guro is a concept or movement or sub-genre, still somewhat loosely defined, that has emerged inside multiple schools of Japanese art and music. The words "ero guro" or "ero guro nansensu" are derived from the English words "erotic grotesque nonsense", and is sometimes shortened to simply guro (though this shortening is usually used to describe pornography). Regardless of nomenclature, the terms guro and ero guro are widely recognized as codewords denoting artwork that depicts extreme/bizarre violence (mutilation, dismemberment, scatology, etc.) in an erotic manner.
