
I only know little since I didn't finished the novel.
SPOILER
Sihyeon's ex is the leader of that other group, the one they call tyrant or something. He did some nastyyyy things to Sihyeon, if I remember they were highschool sweethearts and i think shiyeon was supposed to debut first (not sure about this) also about sihyeon's sponsors i think it was his ex too that made him do it. Shiyeon was so head over heels that he'd do anything for him. The boss cares about shiyeon and he knew about the sponsors too that why he want shiyeon to stop. And Inshu, he knew about the sponsors too and once offered shiyeon for help. That's all I know and remembered so far.

Off topic but Im really glad the ML isnt someone from MC's current life
Like I know even Inshu whatever his name was tried to help the og Sihyeon but like the way he goes about it is really arrogant and cocky.
and plus none of these people even tried helping him in actuality, no one bothered to get to know him, helping him in actual sense.
Can someone spoil me please...
Who's shiyeon's ex? What did the ex do? What's the story about shiyeon's sponsors? What does his boss know? What is Ose's deal? And Inshu, what does he know?
Currently what is Daejun's position in the gang?