It Hurts 'Cause the Pieces to the Puzzle Don't Fit

Marshall and Kat were best friends, Kat had some issues that no one but Marshall knew he was the only one who understood. He never tried to make her eat. Never asked her to stop cutting...as long as she kept her promise.
She couldn't die.
But High School changes people and Marshall met Kim, Kat met Jason and the two went their separate ways.
Now, after 10 years the two of them are forced to face their demons together.