Think The Prince and the Pauper if it was a mecha anime
Then you have Turn A Gundam with the characters Kihel Heim and Dianna Soreil. It's worth knowing that this is one of the notable Gundam anime entries without an English dub.
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First live-action adaptation of Gundam
It was this 1999 film called G-Saviour , which marked the franchise's 20th anniversary.