Thanks for the translation! Very interesting chapter. I wonder if Hyungul is gonna be the voice of reason Jitae needs to get over his current self-loathing issues.
Also, I think after this chapter is pretty safe to make an educated guess about these guys being from The Tunnel. I wonder which type of role will they end up playing during this arc.
If not all of them, at least So-wol and Young-joon being from there is pretty much confirmed. So-wol, Chun-soo, and In-taek seem to know Hyung-chul pretty well.
So-wol and Young-joon are at least acquaintances with Kim Da-hye.
Another thing, since it was heavily implied that Hyungul taught judo to Lim Hyungchul, maybe he's also So-wol's teacher?