Ang kwento ng "Mutya ng Section A" ay isang makulay na salaysay tungkol sa mga karanasan at pagsubok ng isang estudyanteng babae sa kanilang seksyon. Narito ang maikling bersyon ng kwento:
Blood is thicker than water. Or so goes the saying. Demons haunt the Love family for generations. Finally,the family curse has worsen and it's up to Blackforest Psychic Research Co. to finally end it. Even while the try to figure out S' puzzle.