Can an MC be not this insecure for once.
Also who tf goes and talks: "hey do you think they are a couple", "why's she with such a gloomy guy", "maybe he's her brother", "maybe she's an escort", tired of this other's gossiping about trope in mangas. Almost no one does this and even if they do, others most probably can't hear* them. Unless japanese are indeed like this or the mangaka likes to do it.