Yoongi, an abandoned baby who was found by a scientist named Jin. Mutated with cat genes at a very young age, he now posses the strength to transform to and from a cat. Along the way he finds out this wasn't fun and games and that he was transformed for a reason, a reason that benefits everyone but himself. He meets a boy named Taehyung through out the years of his life, an innocence turned reality. Taehyung and his friend Jimin try to figure out about the boy they rarely see over the years but have no idea what is up with him. What happens when they make a promise to each other at a very young age but find out its not that easy in the future, especially if one of them keeps disappearing and hides everything about his life towards the other.