Okay I actually did the math and mutuals sensu strictu make up just over 20% of my followees and 15% of my followers. This is actually a bit higher than I expected, especially on the followee side.

I think this is an undercount, because there's a few cases where I follow someone's main blog and sideblogs (all one mutual but they count as multiple followees) and in at least one case where someone follows my main but I *only* follow their sideblog, thus tumblr doesn't mark us as mutuals at all.

I seem to be making about 800 bookmarks a year on AO3 (based on the last two years full calendar years; I started my account in late 2020)

This includes things that I liked and wanted to save to read again, but also things that I saved to read later.

Excluding my ‘to read’ tag, it’s more like 400 bookmarks per year.

If i’m saving most things to my to-read list before I read them (not sure), AND i’m keeping most of those bookmarks once i’ve finished reading them (that’s true; i have a thing about deleting bookmarks), then I’m clearing about half of my to-read list. Better than I expected!

...for fanfic, anyways. Don’t ask me about my print book to-read pile ^^;;

Yes please, I'd like to see the charts (re: shounen fanfic shipping gender dynamics)

Hahah yes a fellow charts nerd! And so politely asked too <3

(re: this post)

Some explanation: these are the category tags denoting what types of relationships appear in a work (more info here). I’ve highlighted the most popular category for each fandom for ease of reading. Authors can select multiple such tags or none, so the percentages won't add up to 100%. I am looking specifically at Archive of Our Own (henceforth AO3), which has distinct trends and biases from other anime fandom spaces (even other fanfiction spaces). I tried to double check for typos but between my own errors and AO3 database weirdness, take these numbers with a grain of salt. Also, I chose fandoms that I knew to be popular and/or that I personally know pretty well, but I can't be sure that they are representative of shounen anime fandoms as a whole.

Also disclaimer: I'm not endorsing or even sharing personal opinions on any of the specific ships mentioned in this post, just observing their existence and popularity on AO3. Please don't start shipping discourse on my post!

More charts and more thoughts below the cut--

Now, the original thesis was that shounen genre constraints give much more emotional weight to relationships between male characters (especially young male characters) so that's what the fandom focuses on interpreting romantically. Quite a common take around here, and indeed the numbers bear it out. There is some complication on shipping the young characters vs. their mentors which is hidden by the chart -- for example I was surprised that the Mob Psycho 100 tag is majority M/M, because that series felt very non-romantic to me (okay that is a personal opinion). However, a lot fic ships Reigen, not Mob and age mates (still plenty of romance written about the boys, but if you filter out Reigen/* tags then what's left is plurality Gen rather than M/M). I was also surprised that Naruto isn't quite majority M/M, given what I've seen of that fandom, but I don't know it well enough to have any theories.

The big outlier (of the ones I initially thought to check) is Fullmetal Alchemist, especially mangahood. I think this is because despite being a very popular shounen adventure, FMA doesn’t follow the formula in the original post -- Ed & Al (though fanfic & really the original story itself focus more on Ed) aren't trying to become The Best At Alchemy, they already are the best, and because of that, they spend way more time around adults than kids their age. (Maybe I shouldn't have been so surprised that the most popular gay ship in this fandom is Ed/Roy.) They do have a few friends their age – Winry, Ling, and Mei all feature in the top ten ships on AO3. However, by far the most popular ship is Riza/Roy – perhaps because the story focuses more on the adults? That's probably true compared to BNHA and Haikyuu, and maybe Jujutsu Kaisen, but I'm not convinced on the others. (For the record, MP100 and Haikyuu are the other two on here where the most popular ship isn’t doesn’t include the protagonist, but the difference between the number of fics featuring their top ship and the top main character ship isn’t as big.) Maybe Royai are just that much more interesting? Or maybe I’m reading too much into small amounts of cherry picked data :P

Another more tentative hypothesis, but also I think fan writers respond to developed relationships more than well-written(/fan-favorite) female characters. I checked Jujutsu Kaisen because that story gets a lot of praise for its female characters, but this isn’t reflected in it’s AO3 stats at all. From watching the anime, I thought the female characters (at least the students) got roughly the same amount of screen time and development as their male counterparts, but clearly the AO3 portion of the fandom focuses their shipping energies on the latter (and Gojo). JJK is much shorter than the rest of these (so far) and hasn't had as much time develop relationships between it's main cast, so I wonder (if it chooses to add any romance) whether this will be reflected in the AO3 fandom going forward. This isn't a request for manga spoilers (and the manga tag on ao3 is equally gay) but if you've got a manga-based theories or tidbits to share I don't mind hearing them!

(Also I'd argue that the "better written canon relationships" explains the difference distributions in the FMAB and FMA 2003 tags, but that's definitely getting into subjective opinions and probably no one reading this blog cares that much.)

Speaking of JJK, I called that fandom “very horny” in my earlier tags, and here’s what I meant:

(I’m repurposing this one from an older discussion, so the numbers are a bit out of date. Also the way Jujutsu Kaisen is split into manga and anime with no combined tag was an extra complication but I think I combined them properly, and the following discussion is still focused on the anime tag.)

So, a full quarter of the works in the Jujutsu Kaisen (anime) tag are marked explicit. That’s higher than any of the fandoms I checked last year when I was investigating whether AO3 is mostly porn, including Bandom (that is, musician-focused RPF). My sister pointed out that Jojo’s Bizarre Adventure has almost as high %explicit (though it has slightly more gen & teen rated fics), but honestly that one doesn't surprise me. JJK however seemed more sedate when I watched it. (But also not, like, unusually chaste – I’d say typical shounen levels of horniness, which is why the fandom confuses me.) I don’t have any good theories here tbh – if you guys have theories to share I’d be curious, but keep it respectful, I’m not here to bash ANY fic writers.

Finally, I want to be clear that FMA isn't unique, but it might be unusual:

Here's the dozen-ish "Top Anime" (a measure that combines raw popularity and high ratings) from MyAnimeList.com, excluding a few with less than a hundred works on AO3. Some of them skew even more F/M than FMA! However, these ones don’t follow the shounen formula (well maybe Steins;Gate, I’m much less familiar with that one) and are much less popular on AO3 than FMA. The ones that are as popular or more (Attack on Titan, Hunter x Hunter, arguably Gintama) do follow the typical shounen formula, with the expected AO3 stats. I didn’t make a chart (yet), but shoujo (Fruits Basket, Sailor Moon), or adventure shounen with female protagonists (Soul Eater, Promised Neverland) can also get a lot of F/M fics. Some of these are also pretty popular, but none (that I’ve found) are quite as big as FMA. People have also been suggesting adventure/sports shounen well-written F-M or F-F relationships in the notes to the OP (*waves at Gale*) but they all have nonexistent to tiny fandoms on AO3.

Basically, I think FMA is at something like a Pareto Maximum of “makes people care about canon het relationships” and “makes people want to post fic about it on AO3”. It might not be the only one, but it is somewhat unusual, and also my favorite, so it’s the one I wanted to talk about :P

tl;dr -- Minerva is right (not that anyone doubted that I think!), FMA fandom is unusual, JJK fandom is horny.

This post took a while to write because I kept thinking of more fandoms to check and more questions to investigate, so I might make more charts and more posts. Let me know what you think, what I oversimplified, and if you have any suggestions for further investigation!