...renai just means "romance". Hence renai adventure game = romantic/love adventure game.
Leaf created the term "visual novel", which they used on their games which had full screen text. It wasn't a genre name, it was a name of their series of games that had full-screen text.
It was to some extent adopted by other people for use on games with full-screen text, but the genre itself is still adventure.
You don't even know what the fuck you're talking about.