Maybe you could arrange a story arc beforehand. At first the characters mightn't talk much, but then a relationship slowly forms and your character opens up more as it progresses.
Or maybe have a task to do. Even if your character might not talk much about personal things, they'll talk about the task at hand eg. making a plan, and there'll still be some sort of progression.
Edit: I realise I didn't add my reasoning behind this. I don't know about anyone else, but if I RP'ed with someone and they didn't talk much, it would put me off trying again for many reasons. But if they let me know beforehand that there's potential in the long run for some good RP, I'd be happier to stick it out and let grow slowly.
Another idea might be at first have smaller interactions. Say, 10 minutes at a time. They keep bumping into each other (maybe in Jet'a's case, at that Alchemists Guild). That's another way of slowly building a natural relationship, but avoiding the awkwardness if your character might not be very social when you first meet them.
Or maybe have a task to do. Even if your character might not talk much about personal things, they'll talk about the task at hand eg. making a plan, and there'll still be some sort of progression.
Edit: I realise I didn't add my reasoning behind this. I don't know about anyone else, but if I RP'ed with someone and they didn't talk much, it would put me off trying again for many reasons. But if they let me know beforehand that there's potential in the long run for some good RP, I'd be happier to stick it out and let grow slowly.
Another idea might be at first have smaller interactions. Say, 10 minutes at a time. They keep bumping into each other (maybe in Jet'a's case, at that Alchemists Guild). That's another way of slowly building a natural relationship, but avoiding the awkwardness if your character might not be very social when you first meet them.