Yeah I was thinking that too, but then I realised that I also sometimes call close family friends relatives so I’m just gonna continue thinking it’s this and not incest
In Japan (and most Asian countries) people do still marry cousins though, considering they are just saying “relatives” I think they are distant relatives or maybe branch families? Not sure how Branch families work but I don’t think they’re technically related by blood all the time.
they probably seems relatives as close friends, not that they're related, it doesn't seem like that, he doesn't call the mom auntie or something.
are they just going to ignore that they are relatives. i had to go back and check if it was mentioned that he is staying at a relatives house, and he is...lol