It's interesting how something like house locks can be a cultural difference. Where I live, in the vast majority of houses, you could almost say everywhere, you can leave a house and lock the door behind you, without a key.
The only fear i have is the author is a serious erotic fan, almost everything he did wrote is erotic and this manga is like that if u look at the pre serialization. And this is not gonna be different too because he litteraly gonna kiss him. Not sure about you guys but i dont like it