|Demon Beast Invasion is the manga that introduced|
"Tentacle Porn" to a reading audience.
First, to each their own. If a person is aroused by the idea of human/cephalopod love, then more power to them, and congratulations on having an interest that is so widely (and graphically) depicted in manga, anime and the like. Personally, that's not my bag.
It's not that cephalopods aren't interesting and cool. I mean I like squids, I just don't like them like them. So, I would never buy a manga that focused on human/cephalopod love. Not even out of curiosity.
Because I don't want to disparage anyone's erotic interests, allow me to provide the video below, which focuses on hot cuttlefish on cuttlefish action.