The turtle-like shape at the back is created by the obi underneath, surprisingly there is no change in the pattern itself which is the same across the back as a kimono, except that the front is straight, not cut to wrap around the body, and the extra length is kept in place by the heavily padded hem rather than pulled up under the obi in a kind of fitting whilst dressing.
The exaggerated shape of the back seems to accentuate the area of skin at the nape of the neck where this traditionally erotic area is exposed by the low line of the collars.
