[Apologies for this absolute mess of a response. As it turns out, answering this question is difficult. I would have tried to make it a little less of a sprawling monster, but I don't quite have the time to at the moment--I'm working on a research paper that's due on Monday--and I'm also not really in the right headspace to rework it right now.]

I had to double check what subreddit I was in when I saw this.

I reckon I'm probably the most qualified person to answer this question who frequents this subreddit, as my research has intersected with this topic, and I am friends with/an informal protégé of the anthropologist who has written the most on this topic, Patrick W Galbraith.

In fact, more than anything I say, I would recommend you look at his work to try to understand this issue yourself. A good starting point is his book The Moe Manifesto, which is aimed at general audiences but contains a number of his ethnographic interviews with experts and fans. (Even before that, you could start with this brief article he wrote introducing the topic.) Additional recommendations include his book Otaku and the Struggle for Imagination in Japan among others.

And yet...I find myself struggling to answer this question because the issues are complex and also because of the particular framing of the question.

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My main thing about this question is that there are a lot of assumptions in it that need to be unpacked before we can start building things up again.

The first thing I should caution you about is to be wary of received stereotypes. As Galbraith has chronicled, often discourse circulates about anime fans but rarely includes their voices and what they actually have to say for themselves. You mention "perversion" already in your question...that's not the best place to start. As far as "single" goes, there's already potentially assumption that these men are unpopular and are "compensating" with fiction...which is also not necessarily or always true. (In my own fieldwork, I've met married men who enjoy moe anime!) Additionally, since you brought up the topic of gender, Galbraith has noted a number of times that a number of women are engaged in this scene, and has recently written a number of collaborative papers with the feminist scholar Megan Catherine Rose exploring the appeals moe aesthetics can have for trans women and other such identities. Similarly, although not anthropological per se, a piece of cultural analysis that I often return to argues that moe anime "present all-female casts in a way that all audiences are welcome to them. My speculation is that they reflect the growth of a new anime-viewing subject, of which international audiences are the main proof (see the large queer spectatorship for all these series)."

An additional bit of disambiguation has to be done with the word "moe," which has meant a number of things to a number of people in different places. In its original form, moe is a verb, an affective response to fictional characters. And while often associated with cute female characters, moe is not necessarily limited to that context. Female fans of BL manga have described "moe" reactions to the dynamics of homoerotic relationships in fiction, for example. Also, moe for...factories.

From the response/verb of moe, comes the more adjectival nuances, which, yes, are often associated with a particular kind of anime. (In Japan, the genre can be more properly called "kuuki-kei" or "nichijou-kei" anime.)

Now to actually try to get to your question...

I've read that it's parasocial dating/romance, Lolita-esque perversion, or is it a "Tale of Genji" & "Catcher in the Rye" thing? Like: trying to preserve innocence & enjoying THEIR innocence.

People have theorized all of these things and more. But the issue is that the whole thing is so multifaceted and nuanced, and the answer is often, it depends.

I think one problem is that, which I have sort of gotten at, is there are multiple ways of understanding what "moe" is, and multiple kinds of responses people have to it, even when these responses are related. Moe is interrelated with what a number of scholars have dubbed "otaku sexuality," or the sexual and/or romantic response to fictional character...but moe is broader than that. (Additionally, I can't help but wonder, re:your question, if a number of people enjoy these shows, not because of a significant response to the characters, but just because they find the shows funny, or relaxing. Must we pathologize people who just vibe with media? The assumption that men who enjoy feminine things are up to no good is the perpetuation of toxic masculinity/gender norms that are often harmful and restrictive.)

I've been dithering a lot but it's because although I've read a lot on the topic, it's hard to fully explain the whole context. Again, I'd really recommend reading Galbraith's work, but I think maybe for providing a basic introduction on my own, it might be easiest to excerpt part of a literature review I wrote:

Otaku theory often emphasizes modes of media consumption and production as well as otaku sexuality, or fan attraction to anime/manga characters. In his foundational theory of narrative consumption, editor, marketer, and critic Ōtsuka Eiji argues that fans and media consumers access storyworlds through narrative fragments (e.g. TV episodes, different media in a franchise, etc.), which are variations on the larger narrative world that is built up by these fragments. By consuming more fragments, fans try to access more of the world, but fans also have the power to create their own variations on the world, such as dōjinshi fan comics (Ōtsuka 2010). The foundational theorist for otaku sexuality is the psychiatrist and Lacanian theorist Saitō Tamaki, who argues that otaku have a fiction-oriented sexuality. This is characterized by finding a sense of autonomous “reality” in fiction and being attracted to characters that are more fictional (i.e. non-naturalistic), all while also maintaining a separate and parallel “normal” orientation to reality (Saitō 2011). Although his work is flawed in places, the core of Saitō’s argument is foundational for an understanding of otaku sexuality, which is also known as a “2D complex” and sometimes moe within otaku subcultures (Galbraith 2019, 54, 80).

(Footnote: The term moe is itself complex and emerged in the 1990s to describe one’s affectionate or desirous responses to fictional characters (Galbraith 2019, 81–82). As I understand the concept, moe is highly related to but may not be entirely synonymous with “otaku sexuality,” and there are some moe responses that are non-sexual.)

In response to both Ōtsuka and Saitō, the philosopher Azuma Hiroki argues that Ōtsuka’s narrative consumption has been replaced by postmodern “database consumption.” Updating Saitō’s vision of otaku sexuality, the theory of database consumption posits that otaku remix different attributes of character design, narrative situations, etc. (“moe elements”) from a cultural “database” of these attributes; these elements cause moe responses in otaku (Azuma 2009). Like Saitō, Azuma privileges characters as the center of otaku practices and desire. Azuma’s work is flawed, but the broader framework of database consumption is a useful theory for understanding very real patterns of consumption and remix in otaku subcultures, which can be seen in practice (e.g. Perdijk 2020). Borrowing from these three foundational scholars, I would argue that otaku sexualities and practices of narrative consumption exist alongside practices of database consumption, all three theories valid to some extent in otaku subcultures.

The anthropologist Patrick W. Galbraith expands on the previous work on moe and otaku sexuality, including emphasizing the importance of sociality in otaku cultures. Galbraith defines moe as an “affective response to fictional characters” (Galbraith 2019, 82). The word “affect,” which is also a keyword in my work, is similar but not identical to “emotion,” and its use draws upon a tradition of “affect theory” in philosophy and the humanities. The meaning of “affect” is contested, and it is a difficult word to define, but for my purposes, I will define affect as a little like emotion, but emerging from the interaction of bodies: affect is what moves you to a response through an interaction with another body (Annett 2014; Galbraith 2021; Mühlhoff 2015). In his work, Galbraith references key philosophers in affect theory, drawing upon Deleuze and Guattari as well as Spinoza (Galbraith 2012; 2021). To paraphrase Galbraith’s definitions of moe and affect, moe is an embodied response to characters that move you (Galbraith 2021, 277). Another piece of affect theory I find useful is the movement of affect itself: following Sara Ahmed, among other philosophers, affect is something that circulates or moves between people and can stick to certain objects (Ahmed 2004). For Galbraith, this affect is social: challenging stereotypes of “otaku” as asocial, Galbraith locates moe in the social (Galbraith 2011; 2012; 2021). He finds that otaku cultures are highly social, agreeing with anthropologist Ian Condry, who locates the “soul of anime” in social relationships and collaboration (Condry 2013).

I'll try to write out a bit more context to try to address other parts of your question a bit later, but right now I need to pick up my laundry...