Mc dies of sickness and enters an Otome game as the villain's daughter her engagement was annulled at the royal banquet. She wants to save her from doom so she asks the demon king for his hand in marriage. He doesn't say anything but teleport her back to her room. The felon escapes from the barrier and so he trusted her and so she is on the search.
I’m a Villainous Daughter, so I’m going to keep the Last Boss