Yup, there isn't much. Seems to be a real gap.
She only has a minor role so far (with one great sex scene), but Imani in
Maids and Maidens is out of this world and may or may not become one of the main love interests, depending on how the story continues. (Ignore the example images for that game. Imani is not in them and is far more beautiful than all the others. I am saying this as a white man with no
specific interest in black women. Her
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at VNDB gives a rough idea but doesn't do her justice.) Maids and Maidens is a very good game anyway, so do have a look.
In
Sisterly Lust, the MC's best friend is black, and her sister is a potential love interest. However, IIRC she can't be part of the big incest harem ending, or indeed any ending.
I don't know if restaurant owner Victoria in
Solvalley School qualifies as black. She has quite dark skin, but I think her features are more like Asian with a bit of European. But this monumental sex comedy is always a good recommendation anyway. It seems it no longer gets the attention it deserves, now that it has been completed for a while. Incidentally, this game takes the piss on the race topic with the MC's best friend (and his mother) being
green for some reason and how this is treated.
In
Lust Academy, which is basically the Harry Potter story transferred to an American Hogwarts equivalent, Leona is the (dead!) founder of the MC's house and an important love interest. I
think she is black. (Sorry, these things seem to be obvious to Americans, but not so much to us Europeans.) Don't take the hate of that game too seriously. It's actually quite well done, especially in comparison to the wave of boring trainer games started with Witch Trainer. I am not sure what people hate about; I guess the problem is that the emphasis is on the story and the story is just a less talented clone of the Harry Potter story.