Befriended By Satan

A lonely person sells her soul to Satan to have at least one friend. And Satan just goes with it until he realizes at the time of her passing, he genuinely likes her-- maybe even loves her. But Satan can't back out on the contract, so he takes her to hell and puts her in a high position of power. Demons hardened by millennia of torture, now have to respond to a small, shy, quiet girl who has unintentionally become Satan's number one.