Incident

Nine Years ago, an accident at a mysterious factory caused its reactor to go critical and explode, this explosion caused the City of Daiya Chiri (ダイヤちり, Diamond Dust) to be left in ruins and stained the sky red. Not long after this event, children started to be born with what was dubbed "Daiya Syndrome" which caused the children infected to develop special powers and strange abilities. It is revealed that the Shinsekai were involved and were actually responsible for the explosion and the cause for the fall of the old City of Daiya Chiri but also for the rise of the new city from the ruins of the old.