HUNTC-476 What!? 80%? What's this number? A world where the probability of getting laid is visualized and only I can see it! 4 What's that number above your head?!

What's with that number above my head?! I was kicked by a classmate and fell down the stairs, knocking myself unconscious. But when I regained consciousness, I noticed that there were numbers and percentages displayed above the heads of everyone I could see! What on earth are those numbers? However, the numbers went up and down whenever I made a move. This only happened with women. Maybe... I tried various things half-believing, and I realized that this might mean that I could have sex...