Rightwing weebs are currently going nucking futs over Zombie Land Saga featuring a trans character. "Social justice crap gets into anime production because Western influences subvert Japanese culture!"
That's because they got their image of Japan from 2chan wingnuts.
In '01 Futaba (= Two Leaf, and yes, 4chan and its four leaf symbol are based on it) Channel was created as an anime/otaku/underground culture imageboard by refugees and exiles from massively popular textboard 2channel, which is why they were called 2chan.
(The exodus of moot and his goons from Something Awful to set up 4chan is directly inspired by that.)
As outsider/geek communities are prone to through their "be nice to all fellow travelers" paradigm they were soon taken over by extremists.
In this case the extremists were the Netto-uyoku, essentially the alt-right before the alt-right. Extremely Online far-righters who emerged in the 90s as part of Japan's economic stagnation period.
As anime achieved mainstream popularity in the 90s/early 00s, wingnut-occupied 2chan was the primary and sole cultural interface young anime fans had to Japan. Naturally ultra-nationalist 2channers told them all about the Japan that only existed in their heads.
A country where there's no left or right wing (or at least no left wing), no feminism, multiculturalism or other "Western inventions." A country where instead society is absorbed by a unifying monolith of "Japanness."
That, of course, is a bunch of baloney.
Japan is a first-world country existing in the here and now. It stands in dialogue with other countries and has so for centuries.
Feminist thought has been identified in antiquity and queer people have existed as long as the human species.
Chizuko Ueno is a prominent feminist and women's rights activist teaching as a professor at famed Toudai.
The genderless subculture is a growing haven for nonbinary and gender-nonconforming people, boasting a number of trendy public figures and celebs like model Satsuki Nakayama.
Have you ever wondered why anime has generally a pointedly grim picture when it concerns contemporary Japanese politics, with works like Kaiji or Speed Grapher depicting political powerholders as literal monsters?
Japan is a de facto one-party state.
The Liberal Democratic Party has been in power for over half a century thanks to plenty of gerrymandering and other trickery. When they're not corrupt corporate puppets they're part of PM Shinzo Abe's "Japan Conference,"
a ginger group of uber-wingnuts who want to rewrite history books to erase any massacres committed by Imperial Japan, rewrite the Constitution to massively expand the military, rewrite laws to marginalize LGBT people and regularly pray to war criminals at special shrines.
Suffice it to say, they're actually quite hated by large portions of the Japanese population, especially among the younger, more cosmopolitan generations.
And that's why political disenchantment is a common strain across all Japanese works of fiction.
Not that this stops them from getting political anyway, like when they join Antifa!
History is fundamentally multicausal and interdependent, and you need intermediate steps to reach certain outcomes. In our case this was depoliticization as an extension of orientalism. If you frame Asian populations as "inscrutable Easterners" you can erase internal qualities.
Orientalism reduced Asians to aesthetics, general features of architecture or clothing, and scrubbed them off their politics, philosophies and histories.
This held to the 20th century, and in this void of knowledge it took only slight nudges to make Westerners believe bullpucky.
Most of my critics are on the younger side, they didn't experience the state of the early Internet for themselves. At the turn of the millenium, your local library offered easier access and more expansive info than the web.
So imagine being a kid, teen or young adult at that time and being told by a Real Japanese Person (with a hidden agenda) all those fascinating, exotic facts about Japan.
Of course that spread like wildfire, filtering through networks of friends and peers. "I heard from a guy who heard from a guy..."
Echoes of "the Japanese don't care about feminism, environmentalism and whatnot" were present in people who never had visited Futaba and co.
In conclusion, yes, Japanese rightwingers wouldn't have been able to shape weeb perception without the West's power factions holding most of their citizens in ignorance.
TL;DR: Weebs have fallen for the far-right wank fantasy version of Japan and are upset each time they're confronted by reality.