13 Reasons Why, based off Jay Asher's 2007 YA novel, is about putting together the events that led to a young girl named Hannah (Katherine Langford) taking her own life. A teenage boy named Clay (Dylan Minnette) receives a package with 13 audio tapes in it, which were recorded by Hannah to explain, from her perspective, the experiences that led to the last day of her life. She numbered those tapes with a nail polish that is — yup, you guessed it — blue.