Sudden thought I had when checking this chapter.
What if the person that was following Yoo-il in the street lots of chapters ago was actually one of these blue bird stalkers and not the crazy fan (although, she was definitely a red herring)?. This guy said a similar thing to her that this other person did in that chapter about being particularly close to Moo-yi and she thinking she is suddenly "too special" for being close to him (now working as his manager).
The one fan certainly didn't look that brave to take credit for saying something similar, despite doing other creepy things that were reachable on her position.