It's probably just a side-story of what happened during the time-skip of Thug Hero Party while MC was becoming an evil superhero. If you've played the other game then you'll know there is no good end for this character; regardless of which ending you get in the other game this girl ends up as a sex slave.
I guess she's popular among the more butt-hurt nerds for being the only girl who is not a dumb whore so the creator decided to make an entire side game featuring her. My hope is that this side game allows you the her into a dumb whore as well. Also, the last standing picture images of her is more grown up looking than what she looked like in the main game, perhaps it is does have some sequel scenes.