jin is a lonely siren that as predatory  instincts because of them he can’t be around people for to long or his instincts will kick in Causing him to try to eat them so he just avoids people so he doesn’t put them at risk he likes to watch humans from afar but one day he smelled blood and swam towards it to find a human bleeding out in the water so he helped the human and put them in a cave waiting for them to wake up