@CasFujo The guy Juheun was fighting was a detective that I think he hired way back (some time between seasons) to try and take down his family (Juheun's family, cause remember he has a crazy mom).
As for the old lady, I THINK, not sure, but I think it's Juheun's grandma:
Cause I remember in a chapter far back, Juheun's mom and him go to Juheun's rich grandfather (Juheun's mom's father), cause she was kinda written out of the will for not having a son but was brought back into the will when she took in Juheun.