@Rikuhearts79  

My unserious guess is the same, Jo Dan, just because.  No one is paying any attention to him.  They set him up to be a computer genius yet he finds out very little. We have 0 motive but it would be entertaining.

tbh I have suspected him to be a part of gaetal's organization too! I think there are probably other guesses that make sense for the real gaetal but who knows jodan could be in on part of it

I'm just at episode 2, but I can say that:

- In episode 1 the strangest one was the student bumping into Joo Hyun and the teacher (the one sending message to "start" something - Now that I've seen more, also the Red Tumbler and the reaction of the student when Min was trying to keep the runaway still... I don't know, I think Ji Hoon (I'm not sure about his name) is definitely involved. 

- In episode 2, isn't it Joo Hyun in one of the photos of Seok Joo? Protesting, in front of the prison. Also, she knows what Seok Joo said in court, so I think she is involved somehow (maybe just a fangirl or seeking revenge)

- Finally, the prison guard who tries to befriend Moo chan was suspicious.


Okay, I don't know yet xD

I'm now at episode 7 and I think Jihoon is the child the professor was supposed to adopt... and so he blames himself for the death of Narae. That's why I tend to believe Jihoon is Gaetal, while Minsoo/Yunseong is trying to work with Gaetal by doing minor copycat killings (the russian wife) but he's not the real Gaetal. If he was Gaetal, why he should "gift" his mother the Killing vote? Probably he colluded with Gaetal to give this gift. (I'm loving this series, for real).

Tbh, the guess board is pretty much. I always suspected the homeroom teacher but I'm sure he isn't Gaetal. But I'm very much interested in that police hacker, something is definitely suspicious about him. If the quiet school boy and his grandmother are also fans, I don't know what to think again.

Lee Min Soo , I think is the Dog Mask. I think the one who is the mastermind isn’t important . I do think I have seen somewhere him saying to mother. I am the one , giving her proof where he asks her to choose who will die.  I might be mistaken tho. I might have even mistaken wholly a drama if yes and this is from other drama then sorry. I have so many good dramas which I am currently watching and less time so might have mess the stories . 

Lee Min Soo is definitely among those behind the mask, so you guess may be true.