Ok, so here is what I'm thinking: that red haired guy's brother fell in love with one of the brothers, eventually got his heart broken and tried to kill himself. The Prince payed for his treatment and for the family to keep it a secret. Red haired dude got closer to the Prince to find out what really happened. And that incident is what is making the Prince worry so much about his brother's romance with the MC. I'm not sure why the red haired girl hates the Mad Dog so much, but I'm guessing that either she is a tsundere who used to like him and got rejected or someone spread rumors that they were dating and the backlash she got from it made her hate him. Since the Mad Dog is so aggressive and rude, many people must hold a grunge against him but since they can't do anything to him (either because his family is that powerful or they are just scared of him), they are going to bully the easier target: whoever is close to him - if the red haired girl is really telling the truth about not being responsible for trying to kill the MC.
Ok, so here is what I'm thinking: that red haired guy's brother fell in love with one of the brothers, eventually got his heart broken and tried to kill himself. The Prince payed for his treatment and for the family to keep it a secret. Red haired dude got closer to the Prince to find out what really happened. And that incident is what is making the Prince worry so much about his brother's romance with the MC. I'm not sure why the red haired girl hates the Mad Dog so much, but I'm guessing that either she is a tsundere who used to like him and got rejected or someone spread rumors that they were dating and the backlash she got from it made her hate him. Since the Mad Dog is so aggressive and rude, many people must hold a grunge against him but since they can't do anything to him (either because his family is that powerful or they are just scared of him), they are going to bully the easier target: whoever is close to him - if the red haired girl is really telling the truth about not being responsible for trying to kill the MC.
What do you think?