Sorry if this was already discussed, but I didn't know how to phrase it to search the posts.
The dialogue is set up so that if one were to label the characters as Mom/Dad/Sisters it'll sound weird, since the girls refer to the parents as "my" mom/dad, and the MC does not. So, I gather it's meant to be the MC's Aunt/Uncle/Cousins, but I don't have any idea WHY the MC is living with his cousins' family.
I just started and haven't even gotten to the Uncle coming home to lay down the law after happens at the party, and I'm just wondering if it's ever explained why he is there. Feels like the dialogue doesn't fit for immediate family, but the plot/set-up looks like a normal family. They talk like cousins but act like siblings, so it's weird to me, and I'm just wondering if it's ever explained. Like, did something happen to his parents, is there a better school where his cousin lives, something like that?