The promise to her childhood friend Lee Taemin made Soojin choose the life of an idol. Only so she could meet him again. 

Had she known how things would turn out in the end, would she have proceeded to become an idol? Possibly. Because, for some reason, she found herself doing everything for him. Because with that odd feeling in Soojin's stomach, who was she to say no to his request?

Little did she know he was doing everything for her and more just as well. Even things that best friends usually don't do. Because with that odd feeling in Taemin's stomach, who was he to say no to her request?

And of course, if she hadn't become an idol, she wouldn't have met Kai.