"Unnie, do you know the legends of the String of Fate? It varies per culture and it doesn't necessarily need to be red, sometimes it can be gold or silver, then it is said to be of no color when the individuals haven't met or acknowledged each other yet but can always feel that it's there, like some outside force that keeps you binded to your one true love, a cosmic connection between two people since birth that can be felt when you give a little tug on one of your fingers, or that's what they say."

Or, the multiple times where Sakura tugs at the little string on her pinky finger but always receives nothing, and the one time she feels it tugs back.