Hihiii you seem cool w/ systems and also are an Re:Zero fan can we ask you why transfeminine!Subaru is such a popular thing in thr tumblr tags specifically?
(Also, this is not supported by anything at all whatsoever but transfeminine!Subaru × transmasculine!Rem, or maybe transfeminine!Subaru × transmasculine!Emilia, mmmn especially since Rem and Emilia are already quite accepting and enamored with Subarus freak, and also especially w/ the latter Subaru is very very accepting of Emilias freak and everyone elses but he was the FIRST to also stand up for Emilia besides Puck do you see the vision. T4T Emilia and Subaruuuuu we have never thought about it before but that seems veey charming tbh —)
The transfem subaru headcanon (or just trans-subaru / queer subaru in general) is pretty popular due to… well uh pretty much everything going on with Subaru’s gender and his relation to masculinity in the story lololol. (Im going to use he/him here for convenience since thats what he goes by canonically. Anyway)
There are a lot of more nuanced reasons (which you can see on other posts on here! I specifically recommend venxomi’s post on this topic but there are a LOT OF GOOD ONES. We tumblr rezero fans will literally talk about this till the end of time) But the MAIN MAIN thing is the existence of Natsumi Schwartz
Subaru (canonically) on his highschool debut, had the very very awesome and totally normal not at all suspicious idea of dressing up as a girl and “fooling” everyone in his school into believing that he is a girl. Presumably for like the whole school year? There is no text anywhere that states he ever intended to stop. He would have gone on “pretending” for the rest of his highschool life if not for being caught on the third day because of his masculine voice. The damage of being “caught” was actually the main catalyst for his eventual descent into depression and becoming a shut in.
So that would definitely already be enough to trigger a fanbase towards trans headcanons but oh no! No! Theres more! Subaru’s femininity and his persona is something that persists basically throughout the entirety of rezero. Like its literally everywhere in his internal dialogue in the way he refers to himself in the way he talks about his childhood self (ie saying “the passage of time is truly unforgiving” when talking about how he was androgynous and often mistaken for a girl when he was younger. That is in volume 1 btw). But again the most obvious thing to point to is Natsumi Schwartz
Subaru has a female persona called “Natsumi Schwartz” who he refers to as an “idealized version of his own fickle self.” Subaru will like. Take literally any opportunity to be Natsumi. Going out with friends? Natsumi. Wanting to try some chef’s food? Natsumi. Infiltrating a place? Natsumi. And then in literally all of these cases he will drag it out for as long as physically possible. Like way more than what is reasonable for the situation and characters acknowledge this in story too.
Subaru also acts way more confident and sure of himself when living as natsumi. While this is also due to the fact that subaru just, like, hates himself (general) so Natsumi is a way to metaphorically run away from himself, its also because he absolutely loves acting feminine and presenting as feminine. I mean, he could have made his alternate persona a guy, there was nothing stopping him. Why is the idealized version of Natsuki Subaru a woman? <- (and that question right there is basically the starting point for like all of the analysis surrounding Natsumi lol)
Okay im done 😭 i hope thats what yall wanted to hear, again there are a lot of way more detailed posts on here about subaru’s gender nonsense but thats like the essential reasons why. Oh and for why its specifically tumblr? These headcanons actually do exist on rezero twitter, rezero tik tok, etc but tumblr has always been essentially a queer safe space so there are more queer people here to take a lens to that queer interpretation!
Also yes t4t remsuba and t4t emisuba are fucking awesome. Need more transmilia and transrem in my life.