Well that for sure might be an interesting story.
My tip is write about something you know so it will be believable, decide what the tone of the storshould be.will it be hard tragic type of story or will it be also funny sometimes atc…
You wrote thay are misterious…what is misterious about them?
To plot twist - should it be pure romnce or for example also bit mistery atc.that will lead ou to different plot twists so you should decide first this.
ATC.