When a down-on-her-luck student runs out of money—and hope—it's time for the devil to make his entrance and give her an offer she can't refuse. But this devil has problems of his own. He's a cog in Satan's corporate ladder, who's quickly losing credibility because that same desperate girl isn't ready to part with her soul willingly. Now, she's working at his coffee shop while he tries to convince her that she can have it all. And the cost? Merely her mortal soul... (Source: LINE Webtoon)

Devil Number 4 is originally a webtoon series which was officially published in book format by Daewon C.I. (대원씨아이) from August 20, 2019 to April 23, 2021. The series was published digitally in English by LINE Webtoon from August 8, 2019 to March 9, 2021.