The storyline centers on three yōkai—Bem, Bera, and Barro—who arrive in a sprawling seaside metropolis and discover a malignant atmosphere born from human immorality and the havoc wreaked by monsters and yōkai. Choosing to remain, they confront other creatures that threaten people, forming a handful of allies along the way. Despite frequent mistreatment by humans because of their looks, the trio persistently shields the city"s inhabitants from danger, hoping that their deeds will eventually earn them humanity. They battle rogue spirits and corrupt townsfolk, slowly earning respect from those they protect. They dream of becoming human, believing that their selfless acts will eventually grant them a mortal life.