This wasn't part of our contract

When 17 year old Jackie Saint Claire gets attacked by drunk assassins in a hit-and-run murder attempt and is slowly fading, her best friend, Riley Itō, will stop at nothing to save her. Riley makes a deal with a demon..... The deal is simple, Said demon will save Jackie but in return he will get her soul. However he starts to fall for Riley and by the time that the contract is done he simply can't bring himself to say goodbye to Riley. What will happen?