第三教 · Dai Sankyo
Yoko Otoshi 横落
Side Drop
Mechanic
A sacrifice throw: tori deliberately falls onto their own side, sliding an extended leg against the outside of uke's feet. Tori's falling body weight, transmitted through the grips, drags uke sideways over their own blocked feet.
Analogy
Two friends stand holding wrists at the edge of a pool. One suddenly lets themselves fall in, and the raised pool edge catches the other friend's feet while the falling friend's whole weight yanks them sideways, so they pitch helplessly over the coping and into the water too.
Why it maps
The falling friend is tori's sacrificed body weight doing the pulling, and the raised pool edge is tori's extended leg blocking uke's feet: anchored feet plus a great weight dropping beside you equals a sideways crash.