Maybe, but I don't think it counts if both party are intoxicated. It not like yui actually planned to rape mc she doesn't even like him at that time. At best it was a mistake, and It pretty common for people to have drunk sex with strangers. I could count it as rape if even one of them were not intoxicatd . It as simple as she was drunk and Mc didn't really cared that much about it considering it was yui who lost her virginity.
The amount of rape culture from your two comments makes me think I'm on a smut forum or something.
There's levels of intoxication and how it impairs consent, but if MC is so drunk that he doesn't even fully wake up while someone was on top of him having sex with then he's too drunk to consent.
If both parties being drunk meant it didn't count then being drunk would be the number 1 sex assault and rape defense in the world. "Oh no your honour, of course I couldn't rape her,
I was drunk as well."
Now were I in the MC's shoes would I hold it against her, or try to get her punished for it? No, it was fucking hot but it was still rape.
Lastly she thought it was her boss who she had a crush on in that bed, so she was going to go rape him instead. So the mistake wasn't committing rape, the mistake was raping the wrong guy.