The so-called Three Great Heretical Cults of the 2D world are 'Touhou Project', 'Kantai Collection', and 'Love Live!'.
'Touhou Project' is a series of doujin games created by the Japanese doujin game circle Team Shanghai Alice. Related works cover many fields, including anime, manga, and music.
There are probably three things 'Touhou Project' is most famous for—fan art, bullet-hell games, and music.
The one with the greatest presence is probably the fan art. Many people fell into the fandom after seeing the beautiful character designs.
Next are the bullet-hell games, whose difficulty is downright outrageous in the eyes of ordinary people. Players must dodge dense barrages of bullets that dazzle the eyes, focusing all their attention on finding every possible gap and pattern in the attacks. Compared to that, the airplane shooting game 'Raiden' that people played in arcades during childhood wasn't even in the same league, difficulty-wise.
Lastly comes the music. The Three Great Touhou Songs—' Bad Apple!!', 'Scarlet Moonlight, Madly Blooming Eternally', and 'Iro wa Nioedo Chirinuru wo', whose predecessor was 'The Fantastic Legend of Tohno', were all quite famous within ACG circles.
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'Love Live!' could probably be considered the leader of the Three Great Heretical Cults because its influence was the greatest. Awards and scandals surrounding it emerged endlessly. Back in Japan, it could be called a phenomenon-level work within ACG culture.
The economic chain effect derived from it reached as high as 1,000,000,000,000 yen!
That's right—no mistake, no exaggeration!
A full one trillion yen!
Kamiyā Yuu was one of the first otaku to come into contact with this work back then. At the time, the first season of 'Love Live!' hadn't become popular in China at all. Because he really loved the ending song 'Kitto Seishun ga Kikoeru', he enthusiastically recommended it to others.
Strangely enough, after the second season of 'Love Live!' exploded in popularity, he instead lost that enthusiasm. While watching it, all he could think about was how the anime's budget kept getting more and more extravagant.
To this day, 'Kitto Seishun ga Kikoeru' remains his first impression of the series.
As for his second impression, it could probably be listed as one of the most famous memes in ACG culture:
"To save XXXX (a school on the verge of closure, the world, ****...), become idols!"
When watching danmaku videos, people frequently spammed that line.
Additionally, this project was planned with the anime and reality developing simultaneously. Besides the anime itself, there was also the real-life idol group formed by the voice actresses. Their popularity in Japan became so overwhelming that they even entered the Kōhaku Uta Gassen (basically Japan's equivalent of a national New Year's gala).
Originally, the simultaneous real-life and anime project had been extremely successful, attracting huge numbers of idol fans and anime fans alike.
But before long, the drawbacks of the real-life project surfaced.
The voice actress of 'Love Live!' protagonist Kōsaka Honoka, Nitta Emi, became embroiled in a scandal no less explosive than the one involving Aya Hirano, the voice actress of Haruhi Suzumiya, back in the day.
At that time, the entire situation was turbulent beyond belief.
Not only did fans riot, but people even synchronized watching the scandalous adult videos on the NICONICO danmaku website while posting commentary.
The ambiguous reactions from various parts of the Japanese entertainment industry made it impossible to understand what was really happening.
Why was a small magazine able to withstand pressure from industry giant NHK and expose the incident?
Or perhaps NHK had known about it all along, secretly suppressing the matter until after Kōhaku had ended before allowing the information to be released?
For true fans—or for Nitta Emi herself—the truth no longer mattered.
True fans might continue supporting her regardless, but whether the scandal was real or fake, its appearance alone doomed Nitta Emi to being quietly frozen out by the industry.
As for Kamiyā Yuu, he only liked anime and didn't pay much attention to voice actors.
As long as the voice acting was good, other people's private lives had nothing to do with him.
Through this incident, one could see that Japan's entertainment industry was even more distorted than China's.
It had even become an openly acknowledged, unspoken rule that idols were not allowed to date.
Once idols did something that dissatisfied fans, forget sending razor blades in the mail—there had already been cases where people directly showed up with knives and stabbed them.
"Otaku are disgusting."
In China, this phrase was usually more self-deprecating banter than anything serious.
But in Japan, not only did public opinion partly acknowledge it, reality itself genuinely reflected that to some degree.
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Lastly came 'Kantai Collection'.
It was a browser game released by Japan's DMM website. Its unique ship-building and character-raising gameplay attracted the attention of otaku worldwide.
Even in China, many otaku used VPNs to bypass internet restrictions and access Japanese servers just to play the game. This even led to the creation of VPN software specifically for the game called 'Shimakaze GO!'.
Kamiyā Yuu himself had never truly played the original game because he was half a computer idiot. Before transmigrating, aside from gaming and using a few VPN tools, he had no idea what sophisticated things like VPNs actually were, nor did he have veteran players guiding him.
The ship-girl game he played was the Chinese version, 'Warship Girls R'. Since the gameplay systems were fairly similar and could also be played on mobile phones, he simply focused on playing that instead.
There was no need to mention the popularity of 'Kantai Collection' in Japan. The sheer number of doujin books alone was enough to sustain certain gentlemen for a lifetime.
Because of its overwhelming popularity, the browser game also received an anime adaptation.
Unfortunately, the anime adaptation could basically be summarized in one phrase—feeding viewers endless garbage.
If not for the support of the original game's fans, the Blu-ray sales of that anime would probably have become a complete joke.
The 'Warship Girls R' Kamiyā Yuu played and 'Kantai Collection' had sparked countless arguments online. Fans from various ACG forums fought constantly, to the point where some highly populated forums and communities outright banned discussion of both works.
Kamiyā Yuu himself didn't really care.
He was just a player.
Whichever game was more fun, whichever game was more generous toward players—that was the one he would play.
If both games were equally generous, then since he couldn't bypass internet restrictions anyway, Kamiyā Yuu could only play 'Warship Girls R'.
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Besides these universally recognized Three Great Heretical Cults, there were also some relatively niche works, or works labeled as "heretical cults" for various reasons.
For example, 'The Idolmaster', which had already become an outdated title in China, still possessed popularity in Japan, rivaling that of 'Love Live!'. Before 'Love Live!' appeared, it had been the absolute overlord of that genre.
For example, the FFF Brigade from 'Baka and Test: Summon the Beasts'. Kamiyā Yuu himself had once been a member of the FFF Brigade. The FFF Brigade could basically be summarized as the Association of Single Dogs, wielding gasoline and sickles to judge those who had betrayed their principles by obtaining romantic partners.
For example, the American Hasbro animation 'My Little Pony'.
That animation possessed an irresistibly fascinating charm...
Toxic.
And then there were things like the frequently mocked 'Kagerou Project' fanatics, and so on.