One thing that continously kiils me about Chihiro is that he very obviously never stopped internalizing what his bullies said, despite what everyone who defends his arc or even the chapter itself says.
For example, Chihiro wants to become physically stronger. Chihiro, our symbol that represents how true (mental) strength is possible despite being feminine as man, must start hitting weights and take on a more masculine appearance on his journey to become a man. Chihiro doesn't look up people like Sakura, who is both wise and physically strong, (if you really wanted to argue if Chihiro wanted to get fit for completely gender unrelated reasons) but Mondo, the sterotypically macho male delinquent who Chihiro just assume is wise and stoic due to his appearance, despite honestly none of his actions conveying that. Manhood and strength to Chihiro isn't just mental strength, but obviously masculine physical strength, that just happens to imply mental strength.
With this is mind, can we really say that Chihiro truly got over his bullying? Can we really say he learned the true meaning of strength if he still dreamt of being the toxic, reductive image of a man? How can we say that Chihiro really meant it when he said he was man? Whose to say manhood, to Chihiro, didn't feel like something you are only for yourself, but a performance or duty they should've long taken up instead of cowardly living as a girl? A mandatory performance that good men, strong men like Mondo, suck it up and do anyway.
If Chihiro still had very simple, traditional views on gender and a inferiority complex that made him feel weak and stupid for being effeminate, then is it really impossible to say his sudden switch to intense masculinity was just him bucking under pressure, finally becoming a man in the way his bullies always wanted him to?
This isn't even me saying Chihiro is trans/genderqueer. This is me saying Chihiro, as a lonely kid who had an inferiority complex and always felt like they should be a man, even if they always weren't able to force themselves to be the patriarchal idea of one, probably didn't gain the best grip on their gender under the ticking 'get outed as a amab crossdresser to in a 2010s killing game' time bomb.
This is why frustrating to me when I see people say that the only possible way to interpret their character is as a 100% cis man or you didn't understand the story and erasing men who deal with toxic masculinity or whatever. Because like Chihiro's gender is sooo ambiguous because of how obviously they felt the need to be man. Even if you want to interpret chihiro as a guy, I don't think if that moment of coming out to Mondo was made genuinely. I think it was made out of fear and shame, of being discovered as a crossdressing guy before they could disavow his past as a women, and be the first to say how silly, cowardly, and wrong it was for him to live that way. highkey its gives detransitioner now that I think about it.
Chihiro hated being a women not necessarily because it made him feel dysphoric but because it was a sign of weakness. The sign of his failure to be a man. Chihiro was told everyday as a young child that he was stupid, weaker and inhertally lesser for for not properly being a man and he internalized it till day he died.
Even if Chihiro is a guy, he never stopped being afraid of what it would mean if he wasn't.