a story written by a fan of something (ex: anime). there is a website called fanfiction.net that is deticated to fanfictions. but most of it is hetalia yaoi. you could also use deviantart but most of the stuff on there is emo sonic and hetalia fanfics where a mary-sue oc has sex with the writer's favorite character while another character that liked or was there best friend mopes around and ends up commiting suicide. but the oc doesn't give a shit. instead s/he possesses a magical power or something crazy like that. s/he saves the world, and then everyone worships him/her. THE END.
HetaFag: OMG I JUST WROTE A FANFICTION ABOUT RUSSIA AND LATVIA HAVING SEX!
Regular Hetalia Fan: Screw that!