When Taehyung first met Jung Wheein, his soulmate bracelet broke.
His grandma had gotten that soulmate bracelet for him from a famous pagoda and told him: "It will only break if you come face to face with your soulmate. That way you will know it is them. That person is definitely your the one."
So when his bracelet broke, Taehyung was determined that Jung Wheein was his one and only soulmate.