The year is 2222. It has been years since Tears of the New Moon, a mysterious rain, poured and wiped out almost the entire human race. The poisonous rain gave birth to deformed creatures devouring humans, and humanity fled from the danger. As means for survival, the humans then build an underground haven; Amasia. In this newly built dystopian city, in a pursuit of maintaining their existence, they run into an Artificial Intelligence named Magus. Not knowing how things will work between them, the story of how Humans and AI coinciding and trying to find their truths begin.