A pickle is when there is a very small space between two pieces of collision which you can barely squeeze your character through. Because collision between two objects in this game is very rarely flush, there are dozens of potential pickles in JSRF, but due to the random nature of the trick, none of them are viable in speedruns.

The most famous pickle is in Shibuya Terminal, although there are others in Expo Stadium, Skyscraper, and Garage (among other levels).