@Kaarme I've seen it before, but I also wonder if maybe sometimes it's just a mistranslation, or if maybe they just choose to mix and match it with some japanese folklore creature that does have horns.
@RedVanGhoul@Vverg I'm tempted to think the author did it on purpose to make that in-story LN/anime look even more cheap and superficial. It's obviously meant to represent an isekai that relies on nothing but ecchi, harem, and character designs, so calling those oni, or whatever they are, orcs just adds to the cheapness and lazy writing effect the author probably was aiming for. Just the title alone is like from the worst LNs, which would also support my theory of it being a mocking parody.