Stories like this make me glad I'm an adult, working in a field where I'm not expected to perform much gendered behavior. I definitely identify with the POV of the author, I thought so much emphasis on gender was stupid and hated the arbitrary rules (4 years olds shouldn't need to wear shirts in their own houses when it's hot, even if they're girls).
As I got older, I logically understood them and could explain them, but applying them to myself was something I wasn't capable of. It's probably funny, I'm almost always clocked from a distance as female, but, the few times I've worn makeup have been instances that probably fit the definition of dysphoria. I'm happy that I've aged to the point where nobody wastes their breath trying to get me to wear dresses or wear makeup.
Somedays, I'm happy enough with the label "gender nonconforming" others days, "nonbinary/agender" feels better, thankfully when you reach my age, nobody asks your identity so I'm confortable with the lack of specific label. I already have higher than average for AFAB testosterone thanks to lean PCOS, and a thin build + compression bras give me good enough results that I don't care to have surgery.
I look forward to seeing how this story unfolds, I imagine that in some ways it's harder because Japan is socially pretty conservative and gender is more essiential to societal roles there, but maybe also easier for people to grasp the difference because the roles are so defined?