the thought that yukkuri are fast adapting beings was the impulse to draw that feature, the situation is that after being expelled out of the birth canal this particular reimu-ko feels great despair and is fright to the bone, so its systems undergo an unusual process, the heart beat shoots up, its loins growls and twitches,a glue like substances is produce and drips to the "shit canal" a mixture is created and finally the body says evacuate! so this thin but resistant cloth like material shoots out of this manju "shit-hole" and adopts the shape of a parachute, after noticing that her speed is decreasing and maybe wont share the same fate as her siblings or other falling kos, the only thing it can feel is "happinech~"