Vanity Plum's Links
Familial bond.
Peach was Plum's favourite student when he was still a professor. He cares for them like they were his own child and is incredibly protective of them. He's deeply attached and feels at ease when they're around. They've earned his full trust, there isn't a thing he wouldn't do for them.
Plum doesn't like Blue at all, he's an untraceable freak. He keeps tabs on the elusive Blue Roan, reasoning this is necessary to protect those he holds dear, but it's also an effort to calm his own paranoia. He tries to keep as far away from him as possible.
The Lord Blue Roan has little patience for Detective Plum. He also has little respect for him. He also doesn't like him. He also finds him actively annoying. But then because he doesn't respect him or what he does he kinda finds him amusing, which is a big win when it comes to Blue. Occasionally if they're both smashed at the same time and in the same location they hang out and solve crimes badly.