>>715778057
The whole manga is good, you should read it. It follows the school life of people in a world where everyone develops mutant powers or something during puberty. The giantess shows up in the first volume too, so you won't have to wait long to see her.

https://mangadex.org/title/b1d3def7-5384-409e-a946-5993e7ae04a0/dr-hitomi-s-infirmary