Originally Posted by
Calsetes
I don't think that's true - I think you might need to complete Forest Exploration and clear the "gathering trainer" quests that basically guide you through gathering and crafting a ring. One of my characters has the butler's COs unlocked and hasn't even done anything in the Volcanic Caves yet - just unlocked the first mission for them where you kill stuff for points.
There might be another requirement, though, since I always slap some tickets on them to boost them to 20 pretty much right off the bat.