第四教 · Dai Yonkyo
Sumi Gaeshi 隅返
Corner Reversal


Mechanic
Tori drops onto their back beneath uke, hooks an instep into uke's inner thigh, and uses the backward roll to loft uke's hips up and over, flipping them past the corner of their own balance.
Analogy
A parent lies on their back playing 'airplane,' feet planted in the kid's hips, and rocks backward with just a little too much enthusiasm. The kid sails clean over the parent's head, arms out, headed for the couch cushions behind.
Why it maps
The parent's rolling body and lifting foot are exactly tori's backward sacrifice and thigh hook; the passenger's own forward lean supplies the flip.