Chances are she doesn't have any Japanese blood. Their modus operandi was to murder their victims after they'd had their fun.
Anyway, there's more dignified ways to get a green card than shacking up with a pedo fetishist, but whatever floats her boat I guess.
Yuhan claims that she secured permanent resident status prior to the age of 21, and there is little reason to disbelieve her. Given that her Chinese mother and American stepfather appear to have married when Yuhan was a minor, she would have been considered the unmarried daughter of a US citizen for green card purposes. That family preference status is consistent with her timeline.In order to stay in the US, she would either have to have a H1B visa, or a K visa (for marriage). A K visa definitely has a cut-off point of three years, and she can not get a green card unless they've gotten married and lived together for another three to five years.
I think they're using the videos as an argument for ICE later down the line. "See how great and happy we are together?"
She likely had or has a job in Atlanta, but found this shlub and took the path of least resistance.
As for the sleeping in separate rooms until marriage part of the video... Her parents know what's going on if they live together, so there's no need for separate rooms. She's doing that shit to stay away from his weeb ass.