Cro is you're nice, friendly, and ready to help anyone train Conductor. He make's sure you enjoy your stay, while the train moves onto you're next destination. He's friendly to his co-workers and everyone else. Who know’s what’s underneath that mask! Art by c2phos.

From Sweet Dreams and Missing!! 

Lu Ren is someone you could call strange and mysterious. Maybe even weird. No one knows about him. He doesn’t appear in public often. Nothing much to say about him otherwise. Art by c2phos.