Well with Mario and Kim, they're attending events together because I believe they're promoting the car brand that they're spokesperson for, with KimJa it was different. You know in those ch3 signing events, they often pair up the koojins to sit next to each other, NY was right next to Kim and James, or if two actors are currently filming or promoting their upcoming lakorn they would also sit next to each other, so it was so random for Kim and James to sit next to each other and they even got interviewed together too. And KimJa didn't have any connection to any projects or advertisements at the time, so that sparks a huge buzz among James and Kim's fans, especially it's when everyone knew James' going to be in P'Anne's new lakorn, but no one knows who the n'ek is going to be.
But I wouldn't mind seeing Mario and Kim in a lakorn together though

He's one of the many p'ek(s) I want to see Kim pair up with. They are both half Germans which has nothing to do with anything