In pretty sure he's the guy with medium Brown hair and royal blue eyes who is always with the red haired guy.The one who kidnapped him after he didn't complete his kill on the pregnant lady.One of the 2 that came to clean up his apartment when the girls came over and made a mess.
No thats not Lim. Lim wears glasses as you can see here http://www.mangago.zone/read-manga/penthouse_xxx/uu/to_chapter-20/pg-16/
Lim 's Face Revealed by the creator on twitter (second tweet)
https://twitter.com/Bacong_2/status/1206140796212146177?s=19
Me in the comments cause we all wanna know who lim is