Deep within the Black Forest teeming with poisonous mushrooms, a witch named Luna lives alone. With skin that is poisonous to the touch and a breath that will kill if close enough, she is forced to stay secluded from nearby civilization. Even with these conditions, Luna still visits a nearby city to deliver medicine and buy new books to read.

Despite Luna having never done harm to any of the city's residents, many are scared to associate with her, as she is a black witch in a kingdom ruled by white witches. Only able to watch from a distance while people receive her medicine and freely converse with one another, Luna is drawn toward their lives, even if it sometimes means putting herself in danger.