IEMs and anime girls are only really with Moondrop (and now Truthear), Tanchjim, SeeAudio, and that's pretty much it, at least for the more marketed brands.
TANGZU actually has waifus too, but it's them classical Chinese jade beauties (from around Tang Dynasty era). Which reminds me, the TANGZU Wan'er will soon have a beautiful green jade shell variant. Some weeks ago somebody said the green Wan'er will be coming in May or something.
Recently TRN/etc. are doing the Chinese mythical creatures naming scheme too, like Xuanwu (black turtle), Rosefinch (phoenix), et cetera. And they're incorporating the creature names on the actual IEM shell designs, sadly there's no fauna/etc. artwork for the box.
Here's a thread for other/same types of box art for IEMs (some of these IEMs also have different aesthetics for the shell): https://www.reddit.com/r/headphones/comments/10uiyec/iem_of_the_year_this_headphone_of_the_year_that/j7c3xe9/ and https://www.reddit.com/r/headphones/comments/103kuek/truthear_1dd_and_dac/j2zrs44/
Basically right now for the somewhat recent ones:
Tin HiFi C2
TANGZU Zetian Wu
TANGZU x HBB Zetian Wu Heyday Edition
TANGZU Wan'er
SIMGOT EM2R
Reecho SG-01 OVA
Some other artful IEM sets never really get even more of that marketing push.
Ikko OH2
Truthear HOLA
Heart Mirror Zero
Kinera Hodur
Celest Gumiho
Celest Pandamon
Some brands like Shuoer/LETSHUOER and so on also have 3D waifus or actual real life models for the pictures, lol.
There's many more, check Head-Fi/etc. for other box art info. Or check the Facebook groups or Discord servers since a lot of the IEM brands are in there posting their marketing material all the time.
This is crinacle's video on waifu rankings and history, reuploaded on his new channel: https://www.youtube.com/watch?v=OU6E0xDMSUw
Some people on Head-Fi, like AmericanSpirit (the guy that started the Sound Rhyme and JUZEAR threads right now, from the Discovery thread), said that the Moondrop CEO is a huge anime fan, like he posted pictures of it.
And since Moondrop markets a lot of their IEMs through the power of yogurt (or a waifu with some shiny, sticky liquids from like a year and a half ago now), https://www.reddit.com/r/headphones/comments/pfnz82/new_moondrop_waifu/, naturally the memeing lends to easy marketing.
Oh and if Simgot added a waifu for the Simgot EA500, the IEM would sell like hotcakes, this thing is amazing for vocalists from Kpop, Jpop, et cetera. Essentially what a lot of anime/etc. fans will be listening to. The treble can be a bit much but I'm using Final Audio E ear tips right now and it's great so far. If you need more bass, definitely do some parametric EQ to boost it. Keep in mind I listen at lowest volumes possible and so the harshness will be more present for those that listen at way higher volumes than me.
Instead Simgot went for a really classy EA500 packaging, definitely nice but again, might've sold way more or been discovered earlier (Chinese/etc. folks apparently discovered it back in November 11.11 2022 but it's only now that us westerners are hearing about it) if there was a waifu attached on the box art sleeve.
By the way, there are anime girls with some headphones, but yes they're not from the popular/mainstream/audiophile/etc. headphone brands. Remember, headphones are pretty stagnant with the releases and have way less notable brands. And so you're never gonna see the anime-covered headphones as they're usually not reviewed well or known at all.
These days I always see those weird kitsune/cat/etc. ears from some people, notably the ASMRtists/streamers/etc. from China/Asia.
Anyway, don't worry too much about it unless they're sorta bait material, like this Open Audio Witch Pro, lol: https://www.youtube.com/watch?v=e26KH73C4g8
That Open Audio Witch Pro box art is actually normal for us anime fans but for the conservative folks that are used to coverings on the shoulders or legs, it's probably too much as the face of the characters are clearly in that teenager/etc. phase.
Some anime art can get really ecchi or suggestive/sexual/etc. and so stay away from those if you have problems with loli/etc.
Check this Truthear HOLA thread from a month ago where some people are not okay with the convenient sidestepping of the chibi mascot's actual age despite listing every other measurements/info, lmao: https://www.reddit.com/r/headphones/comments/11nryys/the_only_reason_to_buy_chifi_iems_truthear_hola/
Some people didn't get the SeeAudio x Z Reviews Rinko because it crossed the suggestive waifu line for them. But again, for most of us anime fans, it's a normalized or desensitized type of thing.
And so that way more overt waifu (because of the bunny girl boobs pressing against each other with those faces, rofl) of the Rinko might be the start of the escalation of marketing tactics. As for the most part, the previous waifu releases were treading the line with the somewhat glamor/teasing/etc. shots.
Like sex clearly sells, that's why we're all used to the cleavage, legs/skirt, and so on angles. But yes, people have these demarcations and so it's understandable why they don't want even more sexual waifus outside of virtue signaling.
Personally, I was maybe gonna buy the Rinko because I actually like the more regular IEM shell design and to support Zeos (I've been watching Zeos/Z Reviews for like a decade now, he gets a lot of gear that otherwise would've had no reviews/impressions back then).
Oh and the other thing for the Rinko was the planar combo (even though from the start (the $100 pricing sorta hints at it, since there was collab attached, a lot of accessories/etc.) it was likely to be not the 14.xxmm of the 7Hz Timeless, Shuoer S12, etc. or the 13.2mm planar driver KZ have for their PR1 Pro) since that might've been interesting. Other recent planar combos were with Kinera SPD or not as well-reviewed or obscure.
But the early tuning graphs of the Rinko were not to my usual preferences and now there's a whole micro planar and so on drama about it, kinda like Kinera with their SPD stuff. Here's Akros video on the Rinko driver situation, HiFiGo/etc. also released additional images and info: https://www.youtube.com/watch?v=vZtXny4OAto
Oh and apparently Zeos' Patreon people got the Rinko for like $50, so if I'd known that and it wasn't out of stock I might've grabbed one.
Anyway, that Rinko box art is understandably too much. Some of us actually keep the boxes of the IEMs (stored in some drawer, tote box, etc.) and so if they were a more social/etc. person with people going in and out of their room/et cetera it's easy to see why they wouldn't want that displayed.
But seriously, these are just box arts and shouldn't be an issue outside of the initial unboxing experience. We can't really control this aspect of the market as clearly a lot of people like it and so it's free marketing/discussion/engagement/etc. for everyone involved.
I'm a huge anime fan though and these 2D IEM waifus are nothing compared to actual sexual manga/doujinshi/hentai/etc.
Right now a lot of us are enjoying the "Where is My Hammer?" pornhwa with Freyja, Sif, Thor, Loki, et cetera, it has an uncensored version, it's top-tier art.
Midnight Taxi (fallen angel taxi driver, lol) is also really good, but is more black and white, noir style.
Can't believe Japanese doujinshis still don't color their panels. Sigh. And it's so strange how barely any western/Anglo Patreon/pixiv/DeviantArt/etc. artists still haven't made a really popular colored manga or webtoon along the lines of Japanese cultural stuff.
Here, you can watch pornhwa artist Yoongonji draw art for her A Wonderful New World (warning this doujinshi/pornhwa starts off with a ridiculous situation (it's a revenge story) but just power through as the art is godlike), she streams on Twitch/et cetera: https://www.youtube.com/watch?v=SVPhyWTc36c
Imagine if we can get those Korean pornhwa artists to make (obviously not that sexual, more safe for work, less loli/chibi/etc.) IEM box arts, my God. It would attract so many people.
If the Korean IEM companies ever decide to sell overseas like the Chinese/Japanese/etc. IEM makers, we need to beg them to contact the webtoon/pornhwa artists as the COLORED 2D WAIFUS/ART are insane.
As the conclusion to this tangent, sometimes I wish I pursued drawing, those people make so much bank with their Wacom drawing tablets/etc. but the workload is too much and so here I am just raving about art, lol.