Actually, the drawing style doesn't help here: it's pure moe and does a disservice to the seriousness of the theme. I can't take the characters seriously when they act all cute and >.< , say "nya" and go "kyaa" on frilly clothes.
No offense, but it's a bit odd coming from someone called "Nya-chan". I personally will say that if my manga about a bunch of sexual minorities can't be moe, then it can go pack it's bags and move to America or something. Part of the reason I like manga is because they draw the characters cutely, I used to read American comics but a lot of "serious" ones turn me off because, frankly, I find the art style ugly and the people seem to be drawn specifically to be UNattractive.
Tezuka drew cartoony characters in manga that are masterworks of world literature by any standard worth upholding. My two favorite manga probably, Koi Kaze and Yokohama Kaidashi Kikou, both have very cute characters yet handle themes as serious as anything.
If my manga transgender/cross dressing/non-binary/queer characters can't be cute and squee over cute clothes, have teenage drama, love affairs, and be moe while they do it, all the while taking on serious issues, then there is no point to manga and beauty and cuteness. And I will defend the justice of cuteness till I die!