it's open to however the writer wants to play them, but the gist is that their parents died before they were one, so their big brother ~kinno moved them to san francisco until the summer of their freshman year. to be closer to family and to connect with their parents memory more. i'm flexible with either a very close twin relationship, or having them be opposites that don't always attract. or opposites that do attract. i've left it wide open for the writer's muse, basically!