I will try to keep my answer simple. I wouldn’t want to confuse you.
This is a long story. The short version of it is this. Most of the hentai websites out there are blatant thieves. (Blatant - very obvious). There are only one or two websites on the whole Internet that actually paid the creators for their content.
The widespread theft of the pictures has made the people who own them reluctant (not very willing) to sell people rights.
This does not mean it can’t be done, just that it won’t be easy.
To answer your question, I am not Peach Princess staff. I do not know who you would talk to. Someone else might.
Good luck!