This is kind of hard to explain so I drew a nice little picture:
https://i.imgur.com/8jZJePg.png
Basically when you enter the first room after the tunnel you will see Ji-Kun's platform in front of you but if you try to jump down you will just get knocked back. So what you have to do is fall a certain way to get around it, on either side of the waterfall are stone blocks that extend out a few inches further then the waterfall itself. Get on either A or B and run parallel to the waterfall, to the center of it as the arrows show, if you do this right you will not get knocked back into the room but rather fall and eventually get the little wind that carries you back up to Ji-Kun's platform. This does take a little practice and sometimes if done incorrectly you will get pushed under the map, which then dont move at all and simply jump once to get unstuck. Hope this helps people who want dont want to waste time on trash or freak people out in LFR