"The two people connected by the red thread are destined lovers, regardless of time, place, or circumstances. This magical cord may stretch or tangle, but never break"
Oriental legend tells a people destined to meet with a red thread tied to their pinkies. The thread is always tied up, despite the time and distance. No matter how long it takes to meet that person or matter that much time passes without seeing it, not even matter if you live on the other side of the world: the thread will stretch to infinity but never break. This thread comes to you from your birth and take you more or less tense, more or less tangled throughout your whole life
Kangin mentioned that 2 members have returned from enlistment and the rest will have to enlist too. Sungmin and Shindong held their hands tightly behind when Kangin said this