I know it's kinda ridiculous to have two sets of ears, because what would the other pair b...

I'm reading another manga and in there, the animal ears are for them to hear the voices of the animal counterparts, e.g. someone is in their animal form, and you are in your human form, you only need to pop out your animal form to understand them. Cause if you're in your human form, you won't be able to understand the other party in animal form, and I think that's genius. It may not apply here, but idk it makes me feel better that there's an acceptable reason out there existing lol

That actually make alot of sense

Okay, that kinda makes sense. At least it not just there to indicate they're from animal kingdom, it actually is useful