Well hentai is mostly nsfw anime.
You can separate most of them but not all.

I mean, most shows are very clear in their distinction between anime and hentai.
Pretty sure nobody would sort Dragonball into hentai and nobody would put a creative title like "Last Train to Gropesville" into the anime section.
Then again there are shows like Yosuga no Sora which is mostly just another anime but at some point starts branching out into hentai territory.