That's actually a pretty stylish swimwear, especially the part that goes around the neck(but won't it strangle people with big breasts?), the butterfly and sakura petal combo is pretty too. It could use more cloth but it's great.
Methinks it just goes between the breasts and under the "top" (the bra-like part...is there a technical term for that?) to connect with the piece running down the belly. It isn't very well defined, though; it kinda just disappears instead of being clearly connected to either the top or the petal decoration.
