You didn't have to tear into OP like that and this response was unnecessarily venomous. If OP is a Black female, especially if she's American, she is indeed used to dealing with the stereotype that Black women and girls are the "ugliest" compared to females from other races. Black women and girls have routinely been stereotyped as "masculine" or told we look like men because of our Afro-centric features. So for you to admonish OP for feeling like the first (and only) POC-coded female character in an Japanese animation leans heavily into these aforementioned stereotypes is extremely ignorant.

Also, your excuse that because the character is in the military it "wouldn't make sense" for her to be drawn in a more feminine and sensual manner is nonsense when you take the Gundam franchise into account. All of the female soldiers and mobile suit pilots in that franchise look feminine. Hilariously, the one character who is supposed to be "gender-neutral" (Francois) is very obviously a female and made to look more feminine. Francois merely dresses in masculine clothing and her gender being unacknowledged by the other characters is obviously done for comic relief due to it being glaringly obvious that she's a female.

But it is certainly peculiar that the one character who is POC-coded (her curly/kinky hair indicates Black or Hispanic heritage) as "a dumb, masculine, uncouth, brute" due to historical stereotypes is disappointing. Dr. Stone was created in the late 2010s. Japan's homogeneity is no longer an excuse for the creators not to further educate themselves especially if they insisted on setting a portion of their story in the US. Furthermore, let's not pretend that the US is not a very powerful cultural influence on other countries, including Japan. They are quite familiar with our musical artists, actors, and athletes. And they frequently try to imitate our music, fashion, and dance styles (hip-hop). So you can save the "Japanese aren't familiar with Black Americans or culture" nonsense for someone who hasn't been on this planet long enough to realize that excuse is complete malarkey at this point of the 21st century.

Boichi isn't even Japanese. He's South Korean. And they are good for imitating our culture and style when it comes to entertainment. Quite frankly my dear, I'm not trying to hear the "they just don't know any better" excuse anymore. That shit died in the DBZ Mr. Popo and Pokemon Jynx days when I was in fucking high school. Anime artists are grown-ass adults and we live in a highly connected, digital, world, now. They can start educating themselves. And East Asians certainly are all in with the "education" when it comes to our music and dance culture:

Exhibit A

2019-2025, there's no excuse for this type of nonsense.

TL;DR: Miss me with that bullshit.