Okay, so far, for me the most and probably the only attractive characters in terms of looks are Abby and Sasha, what about them? Because judging by Abby's very licentious behaviour, her sexual liberation, it's hard to tell if she's a virgin or not. Also Sasha, given her history, she could very well have been a victim of sexual assault and even sex trafficking, which also makes it hard to tell if she's a virgin.
This is just how I'm reading the situation, so take it with a grain of salt, but I'd say it seems like a pretty safe bet that both Abby and Sasha are virgins. Both of them have way too much of a "good girl" vibe for it to really make sense. In Sasha's case, I did consider that she could be a victim of SA, but I don't see it really fitting the tone of the game or how quickly she perked up after meeting MC. At the very least, I would be really disappointed if she were. I think making a LI a survivor of SA is a pretty overdone trope that seldom adds anything worthwhile to a character that couldn't be gained from some other kind of trauma (in Sasha's case specifically, I think her parent's dying and then being neglected and ultimately abandoned by her relatives is more than enough to give her backstory depth and a place to grow from, adding SA would be wholly unnecessary)
As far as the others go:
-Ellie and Mallory are 100% obvious virgins
-Kana and April are like 90-99% certainty based on what Kana says about boys being intimidated by her and based on Billie saying that all April does is read and watch TV
-Juniper is like 85+% certainty based on how she interacts with her mom and how she hides her true self behind what is essentially a classic tsundere exterior
-Billie is hard to gauge at this point, based on the fact that she is a streamer, I'd say that she is probably just a tease and hasn't really done anything, but I can't quantify my level of certainty
-If any of the students aren't virgins, Lana has to be at the top of the list since she's literally the only one who even kind of has a boyfriend
-Lily and Risa are complete enigmas and I honestly have no idea whatsoever, although I'd say that Lily is more likely to be a virgin than Risa, if only because she seems to be a good natured, heroic character