Basically volture is the enemy because they are after the professor for money (they want the complete blueprintto gain money and power). The professor, hajun's dad, didn't want to complete the blueprint and left his association so people are after him because he is the only one who can finish what he started. Tge professor also treated his family like shit because that was his way of distancing from them to "protect them" from people who are after him.
On the other hand we saw that shihyun's mom, when he just had overcame the truck accident, started working for vulture.
Basically volture is the enemy because they are after the professor for money (they want the complete blueprintto gain money and power). The professor, hajun's dad, didn't want to complete the blueprint and left his association so people are after him because he is the only one who can finish what he started. The professor also treated his family like shit because that was his way of distancing from them to "protect them" from people who are after him.
On the other hand we saw that shihyun's mom, when he just had overcame the truck accident, started working for vulture.
OHHH
Hope it helped <3
I have ADHD and lost interest/my train of thought while reading this 10 times. So in still confused