Summary: I'll be presenting a couple of ways I learned this form from Sensei, this is the original form. The variation will com in a later lesson and I will go into more detail about the tradition the technique originates from and the particular scroll this technique comes from. It's a pretty cool throw, I'm sure you'll agree.
This technique is from the chuden sabaki gata of the Takagiyoshin ryu jutaijutsu, 高木揚心流柔体術. Tori will begin by gripping skin at butsumetsu on both sides and drives their thumb knuckles in and upwards into ribs (kinketsu). As uke resists, tori steps in and executes koshi-nage.
Same as above with the difference being when Unsui Sensei taught this technique in Sweden (2008), were driving the opponent back with the first grip, then when we drove the thumbs into the ribs to lift them from their feet and with this kuzushi. From this point, it would bring them forward to create momentum to throw koshi-nage.
▶️ Watch on DTube
▶️ Watch Source (IPFS)