
I completely support your point.
In chapter 40 akira asks if hime liked her before she told her she was a girl and hime said yes and that she liked akira as a person. it's page 7
Also another supporting point:
In ch 7 pg 6-7, akira says "I can't be anyone's boyfriend" and hime's internal thought bubbles/squares said "Those words made me feel both relieved and depressed". If she originally liked akira as a woman why would that make her depressed? I mean later on like in chapter 13 she realizes her love for akira wasn't because of her gender but there were times earlier where akira was drawn more "manly" and hime having "heart pounding moments" (sorry i don't know how to explain it haha;;), so i think one of the main reasons hime was conflicted about her feelings for akira until chapter 40 (but more so earlier on) when she confesses is that her loving akira meant she wanted or saw akira as a boy (or at least akira would interpret her feelings as so rather than loving her as a person). Of course there's also the fact that akira didn't like hime the same way but i didn't think that was the main reason hime was so conflicted. if hime kind of knew akira was a girl since before she came out and liked her because she's lesbian, wouldn't that have spurred her to confess earlier rather than feel conflicted? If she had been attracted to females from the start and her best friend, who she had feelings for but was "male" until coming out, wouldn't she have felt more confident in confessing? I won't deny hime may have had a feeling that akira wasn't a "normal boy" before coming out which is why she wasn't particularly surprised (although i wouldn't say completely unfazed as if she fully knew all along because there was a panel in ch 1 where hime was speechless) when akira came out but i don't believe that it's because she's a woman that hime fell in love with akira. It just wouldn't make sense why hime became conflicted with her feelings after learning akira was the same gender that she's attracted to when she has always loved akira ever since before her coming out (reread the first 2-3 pages of ch 1).
In regards to a comment OP said earlier on, hime showing no interest in men does not automatically make her lesbian. I'm not saying there's no way she could, but i personally also lean towards hime being pan because she said explicitly that she liked akira as a person regardless of her gender. That being said hime didn't explicitly say she was pan (compared to akira saying "I am a girl" so many times) so she may not be, however it would be a likely assumption that she is pan because she fell in love with the personality not gender. Unless the story shows hime falling in love with another person and how/why she fell in love (official twitter says there's only 3 more chapters after 47 so probably not, therefore we will never know for sure), her sexuality is all an assumption.
I also think yukka's sexuality is also only an assumption, as she only fell in love with one girl and she didn't say she liked girls in general, she just said she liked THAT girl, so we can't just assume she's lesbian. However the mean girls in the last few pages of 16 DID assume she was lesbian (because they said "does that mean she's been watching us up to now?") and we all know what they did was wrong right? Assuming someone's sexuality based on one incident without straight up facts and then claiming it as a fact is equivalent to what those girls did, despite it not meant to be harmful. It's not wrong to have assumptions and some assumptions may be more valid than others when presented with proof, but we all have to realize that they're all just assumptions unless the author explicitly says it's a fact.
Weird seeing people shipping Hime with Hamuro. It's pretty obvious she's a lesbian.