Im having trouble remebering the nanme of this manga I read. Ill try to give a quick summary of it.
The main character is a female highschooler who has long black hair. She meets a pervert who makes dolls. He asks if he can make a doll that looks like her. She agrees, but says he must let her live with him. She goes on to sexually torture and humiliate him for her enjoyment. She works at a sex shop with him and her teacher finds her. He then asks to buy her panties. She says no and when she shakes his hand, she gets cum all on her hand. As the manga goes on, she has to approach the teacher for information. While talking to him, he makes her sit in a way thst her panties are show, as they talk, he jacks himself off.
I really want to find this manga again, it was amusing.

This sounds like the Ibitsu by Okada kazuto. Even if it isn't, which it may not be because I didn't finish it, it may be in the same ballpark.

Also try Sundome, by the same mangaka.