Character AI working on other maps through script?

Hello =)
Probably my request is a little complex, but I was wondering if someone has ever attempted to make something similar (or there already is).

Basically, I would like characters to behave like most 3D games nowdays (or like harvest moon NPCs), even though you're not in a map, characters would follow a schedule of movements.

Of course, more than a functional thing, it's to create more immersion into the game, but I don't know if such thing would work in rpg maker without making lag.

I tried to make it by eventing, But by switching maps the characters would start over as they left, not sure if my request can be done through eventing at all.

Thanks for your time!
And please, let me know your opinions about my request!