Girl's Contract: the Summoned Object Is the Original Devil

The life of the original demon Chaxiu was plain and boring. Since the creation of the world, his job has been to collect evil and balance the operation of the world. There are always people with ulterior motives begging for his help, and most of the time he refuses, occasionally finding some fun with them. This day he received another strange request. Someone actually wanted to sign a summoning contract with him. What stupid mortals. How could it be possible for the incarnation of the dark side of the world, the Lord of Chaos, and the original demon Chaxiu... Wait, if she is a white-haired idiot beautiful girl from a down-to-earth noble family, it seems that she can work part-time as a summoner, isn't that not possible?