Responses
(Spoiler involved)
No not an organization, Jiwoon is the one who’s imitating the plan against red head ; he’s trying to get evidences that red head is bad. You’re right about the rest though, yes. The one who’s messing with them is the red head, that’s why Jiwoon is hiding Suha until the red head is gone from work and Suha can go back to working peacefully.
So... From what I understand, I think that someone/some organization is going after Jiwoon (to the point he says he might turn as a corpse tomorrow morning) and possibly the red hair too (bcs he's in the 'list'). I think Juwoon is hiding Suha not just to protect him from red hair, but also this person/organization that's going after him. Now I understand, he can't let Suha out just like that because he said even just talking in person with Ms. Choi can bring suspicion to her, let alone Jiwoon's secretary (Suha). I think he's afraid of involving Suha, that's why he didn't tell him anything