It shouldn't be in the game. Within seven minutes of playing it, I immediately made a post in the OT basically saying "Jesus Christ why is this girl naked in a mech". That said, the issue was immediately dropped, it's never mentioned again until the final scenes when it's contextualized, and minus the slightly risque Iori and Tomi shots, isn't really sexualized at all.
I'm a little more annoyed at the (adult) Morimura skin-tight black latex body suit FOR NO REASON. I don't even care if she's large chested, that's just ridiculous. I guess it's an improvement over previous Vanillaware titles, but ugh, I rolled my eyes every time she was on screen.
If you're turned off by that stuff, you're well within your rights. Despite the many positive qualities of the game, developers should always listen and strive to better. You telling them that this stuff (easily fixable) isn't acceptable is a perfectly valid way to express your discontent.