Both of which barely any anime or popculture idol can offer. Or rather, both things that none of their “worshippers” search for actively in their worship.
Religious devotion is different in that, most of it DEMANDS devotion, while all of today’s idols and popculture, although expecting and hoping for devotion (so it can sell, or simply for self-gratification of the author) does not demand it. And while it transports values often – for example Shonen series – it doesnt actually teach them as the media is different. There is no complex of values given to the viewer with the implication of divine retribution or at least karmic consequences here (which even buddhism has, albeit in a different, mostly positive enforcing way).

As such, elements are similar, but only superficially so. Haruhiism is no religion.
It’s just a fancy name for expressing fan devotion, capitalising on Haruhi (in her show’s) position as something akin to a god.
Neither of the followers will adopt values from it, except perhaps if they overlay existing value system on the show, and so exchange the SYMBOL of their belief.
(For example, with discordianism, equaling Haruhi with Discordia/Eris)

An interesting parallel to this is the Lousiana Voodoo:
Practised solely by creole, spanish and french speaking afro-american slaves, it essentially equates the original, more nature-spirit like Loa gods of the Voodoo pantheon with Christian Saints, most notably Papa Legba, keeper of the keys and lord of pathways, with Petrus the keeper of Heaven’s gate.
It is said that this is because they tried to stay hidden, but I is matter of actual identification too, as the actual properties of the saints and loas mixed.

Anyway, the point is, even if there is shinto gods and mystical animals (the giant animals in mononoke are also kami, remember? And Shinigami…) in anime, no, even though it is prevalent throughout it, this is of no more religious significance than the religious symbolism in NGE. No, probably even lesser:
At least to western audiences (japanese probably too) these spiritual, divine things are just as believable as giant mecha, magical girls and Kung Fu masters that fire balls of energy from their hands: Not at all.
To every somewhate sane and healthy person, it is patently obvious that they are fiction. At most, it can sprout interest into the actual idea, the actual religion behind it, or in the case of japan, appeal to nostalgia or one’s already held believes.

Plus, I’d like to point out that, although apparently it’s prevalent through most languages, “I believe in you” and “I believe in god” is a different sort of believing altogether. The latter means “I believe a god exists” The second, actually means “I believe in your abilities / quality of character / that you can do it” .. something altogether different.
It’s interesting that this is often correlated in the case were gods /beings are characterised by the belief of their followers.
You don’t need to believe in persons. Knowledge defeats the need for believe. As such, telling a god you believe in it in this kind is paradox, as, obviously, it’s there if you cant talk to it, touch it etc. Similarily, what Nagi and Zange accumulate is not belief – you very well belief they exist here – it’s devotion.

You can very well believe there is a god and hate him though that’s rare.
The only belief in anime however, is the one that it’s a person.
And of course, the suspension of disbelief.

It made JP2 a very popular pope, as it endeared him to whole nations to say the least about specific locales (though all momentum he made reaching out was undermined by the pedophilic scandals of late).

I wonder, is this the case precisely because of the nature of the medium? This could be especially true if fetishization = fanservice = wish fulfillment.

The Philippines is a good example of a religious colony rewriting the colonial master narrative. The black Jesus above is an example, and there are other subtle linguistic ones as well.

You’re definitely right about the hierarchy, and the process, and everything. I did actually know something about the process beforehand, but the book A Canticle for Leibowitz has a lot of stuff about the process, given that it’s (in part) about a monastery dedicated to a religious figure who has only been beautified at the book’s start. Of course, he was a scientist, but they don’t really know that…

Zange, on the other hand, is portrayed as cute and also pure–but we find out rather rapidly that that seems to be a front, when she has the whole pseudo-BDSM scene with Nagi in the gym shed.

If we take Nagi and Zange as stand-ins for Shintoism and Christianity, respectively, then we get an interesting representation of the dialogue between Japan and the Western world: Nagi seems outwardly a little strange but kind at heart, but Zange is the obverse, almost literally whoring herself out for 100 yen in order to attract fans/believers. Zange’s oft-brutal (in the ero-comedic way) treatment of Nagi could perhaps be read as an attempt by the West (through Christianity) to cause Japan (through Shintoism) to submit themselves to the West. Even more amusing, in order to fight against the growing popularity of idol-Zange, Nagi, too, has to try to be an “idol”–almost literally, considering how she acquired her physical form in episode 1. It’s a fairly common outsider’s view of Christianity (or any evangelical religion, really) encroaching on the local religion–those falling for the “invader” religion are literally buying into whoredom.

Amusingly, Jews and Greco-Roman Gentiles thought this of Christians in the early days of the religion–Gentiles because the concept of monotheism was kind of strange to them (also their problem with Judaism), although Gentiles of the time never really minded people doing other religions as long as they left well enough alone, and also because of the propensity of Christians to be cannibals (the Eucharist–what do you mean you’re eating his body and drinking his blood?); and Jews because non-believing Jews refused to admit that Jesus was the messiah promised in the bubbling font of apocalyptic literature pouring out after the Roman conquest. Christianity started out as a sect of Judaism reviled and/or scorned by Jews and Gentiles equally, sticking it in the same position that it would later cause as it spread across the world. Not to even mention all the crazy sects of Christianity that cropped up and refused to die out.

Is this all coincindental? I’m pretty sure it is–Nagi never really shows up in the aforementioned fetishized miko garb, but Zange was, most likely, portrayed as a nun(-like entity) because of the similar fetish for nuns in Christian societies (and/or Catholic schoolgirls) that overlapped into Japan. Perhaps this kind of subtext was in the back of Eri’s mind as she drew the series (or running through her head while she couldn’t move) or perhaps it wasn’t; most likely it’s just a collective cultural thought surfacing itself in popular culture, which makes it both unconsciously intentional and consciously unintentional.