Chicago's hundred Magical Girls, united under a theocratic Empress, plan to expand their territory. Except Laila, Chicago's bookkeeper. Cushy job, couldn't care less about conquest—until she's assigned to Chicago's invasion of St. Louis. Yeah, maybe this "Empire" thing's not so hot. Maybe it's time to get out. But the bigger an empire gets, the harder it is to escape...

Kaguya kills a man. Mokou kills some rabbits. Past events repeat themselves. Mokou realizes how pointless its all been, and in her despair she decides to permanently leave the Bamboo Forest Of The Lost. What follows is a chain of events that encompasses all of Gensokyo.