Collided worlds

"What was the point of leaving a life where you had to
spill blood for a living only to be stuck in a similar one?"

After running away from her duties as the heir of the Demon, king of assassins, Katherine found herself in the modern world. A world her parents kept her away from. She immediately took a liking to the world before her and its people until she was kidnapped and encountered the a mafia leader whom she can't control her feelings around. Soon, they realize they face common enemies and must work together to win the upcoming war.