The king eats everything in the world.

One night, high school student Komatsu Yukari was attacked by a bizarre killer named "Umbrella Stand." Before he's about to die though, he is saved by a strange woman who introduces herself as the "Bad King," a being whose goal it is to devour all the evil in the world. But why does she resemble Komatsu's deceased older sister Karen who was only recently killed by Umbrella Stand?