Metafiction tech
External attributes of the VN (such as it being a work of fiction, or a computer program, or a 2D representation on a screen, or being influenced by a player, etc.) are themselves relevant to the plot of the VN. This may range from just regularly breaking the fourth wall to more subtle plot constructions. Check the related [url=http://en.wikipedia.org./wiki/Metafiction]Wikipedia[/url] article for details.
No games carry this tag yet.