Diagram of how I drew it

This is what I thought when designing the back based on the front structure: (even if there's room to expand the fabric coverage) there's just way too much butt showing. But since she's a lewd brat, I think it's perfectly fine for her ass to be out this much.

Also, if you look at her from the side, isn't she basically naked? But since she's a lewd brat, I think that level of exposure—looking almost completely naked from the side—is just right.

(That's what I thought when I drew the diagram, but maybe she doesn't look that naked...)

In the end, the sexiest part is definitely the breast area, which is barely any fabric at all... Thanks to the prominence of the strings, the overall feeling of it being "just a piece of cloth stretched over her" is incredible, and it's just so lewd...