I was about to post on the model thread to complain how gundam was dying as we don't get any new shows, here it comes XD
Witch from Mercury...sounds like someone got abandoned in Mercury and the descendants are trying to take revenge...
Don't know why, my immediate thought about this title is....the show could play it out like Princess Mononoke for some reason? (even tho I did not really watch that film at all)
The main character is the earthling and he meets the mysterious female gundam pilot who claims that she came from Mercury....