According to the character stat panel, they are both the same height, though there is a couple kg discrepancy in their weights. Mia seems to have green eyes, like Venus. Alice & Jade have green eyes, but are quite a bit shorter.
If Mia had just recognized the MC as the hero who had saved her bag, why would she want to pretend she didn't know him? On the other hand, if Venus recognized the MC as the hero who saved her bag, she might want to show him an extra good time in the strip-club; then be embarrassed when she saw him at school....
Hmm, strange indeed, they really did not look similar in height in the game, but we haven't seen that much of Mia yet. Completely forgot to check those stats actually
We don't know what Mia was doing in that alley in the first place either. And I did not think she was that embarrassed in the classroom and MC himself was the one to express doubt on having met her, so it could just be she toned it down due to that.
But as I already said, not impossible. And of course the two separate character panels could just be our resident panda bamboozling us. I just did not think the evidence was enough
yet. But it would of course explain why she was there. To me however Venus made somewhat of an experienced expression compared to Mia, but maybe I am just overstretching that with how little interaction we had with Mia so far.
Also I just enjoy disputing this for the sake of doing so
This game definitely deserves lore and story discussions because of how well the world is built and that kind of animates me to debate about these things.