Y/n is Jim streets little sibling and is still in high school. They spend a lot of time around the team and at the precinct with them. Y/n is 15 and today is the last day of summer, the next day is the first day of the new school year. They have a best friend Mattheo Riddle who they have know since they were 2. Mattheo is only a couple months older with his birthday being in March and y/ns in June. They are almost always around each other so Jim and the team know who he is and have met him multiple times. They are going into sophomore year. Y/n lives with Jim and has for awhile. Both their parents are dead just like in the show.