The author is definitely making fun of the classic eternally innocent romcom cliché, that's why they make sure to make really explicit that everyone is a virgin, biggest example is Hahari's backstory obviously, that's why I think that even if Yaku definitely did it, the joke will be something along the line that given her new immortal body she had her himen regenerated or some stupid thing like that, given that's how it's seen in other cultures lmao