Nana lives as a ghost. She can travel to various worlds, play different people, and accept strange tasks.
For example, as a criminal woman and the task is to escape from prison. As a beloved concubine, her mission was to guide the king to focus on his feelings and ignore the government affairs. He was once a young man, and his mission was to become a feared flower-picking thief in the world.
Waiting for strange tasks, Nana plays various lives. Because she completed the mission very well, she was given the inexplicable title of "Little Expert in Mission Accomplishment".