I like this game a lot. The story is good without the masses of dialog that you sometimes have to wade through. I have only three suggestions. 1) It seems like there should be random encounters with girls outside the main story line. As it is, the progression is slow. 2) I think there should be a more obviously hint system. Digging into the Cain menu into each character, over and over, is annoying. If there is a hint for a character, that should be obvious on the navigation screen, or the Cain menu should be flattened. 3) I'd suggest adding the "return" button to the top of the screens as well.
So for suggestion one, I do see your argument, but I think having continued events with one girl that are interesting scenes, and not just sex, is better. There are some random girl sex scenes, but I don't expect to do many of those. Although random encounters in general isn't a bad idea, and I will probably implement that.
Suggestion two, you can track a guide, and it will be on the right side bar. That way you don't have to go back for each step, just keep the right side bar open, and it will automatically update. That being said, I might rework the Cain page down the line. It is getting cluttered.
Suggestion three, do you mean in locations?