I'm not on it now, so I can't give a detailed description
Okay, create a common event set to "none" to call it. Name it "Character choose"
Create a choice.
1. Boy1
Change actor to the sprite you choose
Erase event
2. Boy2
Change actor to the sprite you choose
Erase event
3. Boy3
Change Actor to the sprite you choose
Erase event
4. More
1. Girl1
Change Actor to the sprite you choose
Erase event
2. Girl2
Change Actor to the sprite you choose
Erase event
3. Girl 3
Change Actor to the sprite you choose
Erase event
4. Leave this blank.
Now create an event on the first map, set to "autorun" or "auto go" or whatever.
Set the event to say "call common event" and then character choose.
Show text "keep appearance?"
Show choises "Yes, no"
Yes - Erase event
No - Call common event "Character choose"
And I think that should do it.
If theres any problems, tell me.
Theres a 50% chance it will freeze, I will pull it up and try it. I just thought this up, so I'm curious if it will work.