The Pinky Square is a variation of the Pinky Swear
In this variation, the two parties involved proceed with a regular Pinky Swear, locking Pinky fingers together while making a promise. The Pinky Square takes this promise one step further by then having the two parties move their interlocked pinkies in the shape of a square, thereby locking the promise in a proverbial box, thus creating a stronger promise.
Traditionally the pair will move their pinkies in the order of down, right, up, left, and down once more, with the final movement overlapping the first and thereby sealing the square to ensure that neither party may break this promise.
Breaking a Pinky Square can, depending on the parties involved, be punishable by death
so both parties are advised to discuss the possible ramifications of a broken promise before entering into a Pinky Square agreement.