Actually, i'dd say American Comics do this most often, while with Japanese manga a half sexualizes, while the other doesn't, problem is largelly the role of the female characters.
There's also a large difference between sexualising men and women, most american comics are targeted at a male audience, and the way men are presented is mostly as a self fantasy, since they are presented in "masculine" positions, with women, they are not, they're not being empowered by the experience, there are a lot of images parodying that actually, but right now this was the best i could find:
If it was a man (you never see something like that actually):
Imagine a man in her position now too:
Most female characters have the bodies of porn stars except for a few exceptions now and then, though men also have a similar problem, it seems like they are a bit more varied, but that's a story for another day, since the art itself is much more subjective.
It's not completelly wrong to sexualize a character now and then, i won't really criticise Power Girl because the "window" is one of he most known elements of the design, but it shouldn't be the norm as it is right now.
About anime/ manga, it seems like the audience is more varied, so men aro sexualised a lot of times too, just not in shonens. While the treatmen of women is sometimes laughable, they also have more stories geared towards them, the audience of their mangas are Basically split in men and women, which is more than i can say for American Comics.