.... I actually thought it would be funny if he accidentally crafts the real deal and put it on her before they figured out it's not just a fake collar.
Not really... Not in the sense "the West" uses "Hentai" in this context. It's not outright pornography with extreme elements.
More a "whish it were me" Eroge featuring FemDom ( with alllll of the Tropes.. ) and Monster Girls.
A pretty tame funny take on the fetish as well, and at least the MC isn't a Shota or an outright wet rag for a change.
Yea, I read the LN a while ago, while it does mention they do it. It never gets any real graphic detail about anything. I guess the manga version is trying to get more readers by being a little more detailed.
Then again, its been a long time since I read the LN, I could be mistaken.