I really appreciate that you repulse to rape, perhaps you should consider adding a content where a relationship with the cafe owner is possible while keep maintaining the innocence route. So it's much more about the mc's choice, not through coercion.
I think there should be other reason people forming a love and lust relationship; not always about big dick, threat/blackmail or physical appearance. Something that come from much more deeper feeling like sympathy, respect, fondness, which feeling is so strong that it's end up stronger than the age or physical gap that they have between them, creating a very unlikely scenario where both are consent despite all the odds. Because it would not be interesting if the mc is willing because she is a bitch, it's more valuable if she is noble and value herself well, and despite all of that she give in for a good reason.