I been thinking bout this since day 1, but I think he killed his own dad.

i literally saw a tiktok on this theory, that he’s not a great narrator of his own life. and the more this goes on, the more i think he did.

My theory is that Guwon witnessed Jinwoo's dad hurting him and took him out.

Maybe the dad was evil and he doesn't remember and Guwon found him killing his dad and that's whi he thinks they're alike.