I'm a bit confused, would love to learn. The Potsdam agreement said that Japan controls is main islands (the ones right by the mainland) and the other minor islands (anything not right next to the main island) would be determine by the Allies later. This was signed by China and obviously has been followed.

Then the Treaty of San Francisco (which didn't involve China signing or agreement or anything) said that the Allies would revert control of Okinawa to Japan, which was the Allies choice at that point given that they were in control as stipulated by the Potsdam agreement.

What's the gap between what was said and what happened? You could argue that the WW2 agreements were unfair and didn't follow historical ownership but I'm not sure which part of the agreements themselves was directly violated.