Something I realized about Udonge's ears

[GuardianTempest]

For a long time we've wondered what's up with Reisen's ears and whether or not its fake. I don't have a definite stance on that but I had a realization that its appearance helps her stay in the Human Village. If her hat ever falls off while visiting, she can simply claim that she's wearing a costume or that she's trying to avoid getting the attention of youkai by looking like a non-human.

"Wow that's really nifty, can you remove those ears?"

"Yes but not right now, I'm kinda busy selling medicine at the moment." // "I would but it takes a lot of time and a screwdriver to pull these off."

"Alright, just show me when you're done...if ever." // "What's a screwdriver?"

[Tengukami]

OK.

Now explain Orin.

[Hope ♦ Metal]

OK.

Now explain Orin.

Freak alchemy accident.

[Sagus]

OK.

Now explain Orin.

Her human transformation is actually perfect, but she wears a nekomimi tiara because she thinks she's being clever.

[Tengukami]

Personal theory wrt Orin: the human ears are for hearing everything, but the cat ears are specifically for hearing the tormented howls of the dead roasting in hell.

[aListers]

The only thing I noticed about Reisen's ears are that they're more scrunched up than every other moon rabbit's ears - theirs tend to be smooth while Reisen's are always scrunched up to some extent. I assume I'm thinking too hard.

[GuardianTempest]

OK.

Now explain Orin.

Uh...

Hell's Traffic Accident, right? There was some sort of "collision" in regards to her creation, somehow a cat and a humanoid clashed and had their traits fused.

[Drake]

Reisen has only worn ear clips in about half her appearances (IN, PoFV, and FS 22 being most significant). She doesn't have them in SWR nor LoLK, along with a few appearances in manga.

Meanwhile, we see that Seiran also has ear clips, just not attached to the base of her ears. If anything, this should show that rabbit youkai will use ear accessories in general.

aListers: Judging by Seiran having taller ears, and Ringo and Rei'sen having floppy ears, it's probably just that different rabbits have different ears.

[Sagus]

aListers: Judging by Seiran having taller ears, and Ringo and Rei'sen having floppy ears, it's probably just that different rabbits have different ears.

Reisen's ears are the only ones that look like crumpled paper though (which's what I assume he meant by them being "scrunched "), at least in ZUN's art.

Probably just means what you said anyway, different rabbits have different ears.

[haoreos2]

In the same way Kogasa is the umbrella, Orin is actually the hair and ears, sitting on and puppeteering a long dead corpse for communication purposes.

[GuardianTempest]

Reisen has only worn ear clips in about half her appearances (IN, PoFV, and FS 22 being most significant). She doesn't have them in SWR nor LoLK, along with a few appearances in manga.

Meanwhile, we see that Seiran also has ear clips, just not attached to the base of her ears. If anything, this should show that rabbit youkai will use ear accessories in general.

aListers: Judging by Seiran having taller ears, and Ringo and Rei'sen having floppy ears, it's probably just that different rabbits have different ears.

The ear accessories might be a form of gadget that disguises the Lunarian as a rabbit youkai at the same time. They change them out when they're wearing the lunarian helmets, which come with "ears" by default.

[Fastest Thing Alive]

The ear accessories might be a form of gadget that disguises the Lunarian as a rabbit youkai at the same time. They change them out when they're wearing the lunarian helmets, which come with "ears" by default.

Lunarians and Moon Rabbits are separate things though, not the same thing.

[Drake]

could also just be ear clips

[GuardianTempest]

Lunarians and Moon Rabbits are separate things though, not the same thing.

I've been away from the fandom far too long.

could also just be ear clips

Weird, either those are some huge decorative hair clips or button-clips are placed poorly.

[Sagus]

could also just be ear clips

no, they're the lunarian equivalent of a cyanide pill

or, they're bombs to be remotely activated by their lunarian masters when the rabbits get into the right position

or, or, they're the microchips that the lunarians use to mentally control the rabbits

or, or, or, they're the target locators for the giant lunarian orbital laser station

[Tengukami]

Weird, either those are some huge decorative hair clips or button-clips are placed poorly.

Not actually that weird. I think it makes sense to apply Occam's Razor and what we already know from canon when it comes to speculations like this, and ear clips makes more sense than Lunarians In Disguise, to me anyway.

e: OK I admit "mind control devices" has a lot of comedy appeal.

[Abraham Lincoln]

I always thought Reisen's ears looked "scrunched" because she sometimes puts on headgear, as OP has already mentioned earlier. She has to scrunch them up in order to fit them inside her hats.