Right... hentai is considered "hardcore" or "softcore" where nudity is obviously emphasized.
This doesn't really happen on Adult Swim. There might be mild nudity in a humorous sense such as Family Guy nudity (the deaf greased naked guy running around), or random anime comedy nudity (some ninja is viewed naked from behind), etc... but not tits, nipples, or sex. 
If you want hentai, go to your local mom-n-pop video rental store. 
