It's very clear at Jaeha's parents didn't take care of Yoseob and Jaeha that well. They had good intentions but they literally trusted a kid to tell them not to bring Yoseob to a doctor, you can't adopt a kid who was abused and leave them with another kid. This was a conbuting factor into Yoseob's actions, it wasn't anyone fault that he killed but they did conbute to his descent, all because the 'father' adopted a kid he felt pity for. DON'T ADOPT KIDS BECAUSE YOU FEEL BAD, BUT BECAUSE YOU CARE AND YOU HAVE TIME TO LOOK AFTER THEM!!
It's very clear at Jaeha's parents didn't take care of Yoseob and Jaeha that well. They had good intentions but they literally trusted a kid to tell them not to bring Yoseob to a doctor, you can't adopt a kid who was abused and leave them with another kid. This was a conbuting factor into Yoseob's actions, it wasn't anyone fault that he killed but they did conbute to his descent, all because the 'father' adopted a kid he felt pity for. DON'T ADOPT KIDS BECAUSE YOU FEEL BAD, BUT BECAUSE YOU CARE AND YOU HAVE TIME TO LOOK AFTER THEM!!