I can't help thinking, it is what it is so I won't bother looking for an in-universe explanation, but it seems funny to me the way they really zero in on the human/beastkin divide as the sole hurdle to the relationship. Like, to the point where it's pretty conspicuous the way they all avoid the elephant in the room. Based on the way the publisher character (forgot her name :p) reacted, this isn't some alt-universe where adult/child couples are considered the norm or even culturally acceptable, but nobody else even bats an eye. The same-sex taboo doesn't even register at this point, but even then, I wonder if that's seen as okay? If this story shares a universe with the other beastkin series, the beastkin nation is said to be unique in treating it as normal. Of course the meta reason is that the narrative would be weighed down by dealing with too many taboos, but the mangaka still wanted to tailor the relationship to their, uh, very particular taste.