For the top part, I would suggest putting a zipper down the back and just matching up all the gold designs right to the edges of the zipper. You have to compensate somewhere since most anime designs don't have seams or closures because that's not something they need to worry about.
As for her tube top, I wouldn't construct it like a tube top, but a full bodice. I would make it have seams that fit you closely and then put some boning in the seams to help hold it up. That will give the extra support needed to keep a top that shape up. And then down the back again you could add a zipper to make it easy to dress.