Manga Magic Marriage

According to tradition, witches are supposed to be wed to demons as wives. The more magical power contained by the witches, the higher they are sought after by the demon races for prestige, power, bloodline, and fame. 16 year-old Sunya Velladonna decides to break this marriage, forced onto her by the demon world, and decided to escape to the human realm.

While in the human realm, she encountered a recently divorced young doctor, Othder Hurvenss. In order not to be caught and sent back to demon realm, Sunya took the opportunity to make a magic marriage contract with Dr. Othder while he was sleeping.

With both of them facing marital difficulties and having coincidentally met each other, what will happen to this pair and will occur?