The Black Egg Affair (黒卵の件, Kokuran no Ken), also known as the Foremost Atrocity (残虐行為の中で最前線, Zangyaku kōi no naka de saizensen; Lit. "Foremost among atrocities"), refers to the events surrounding a curse seal administered by Tamamo Irigami. A set of ten school-aged children, all Reincarnates of the Irigami clan, who were given the Start of the Waning Moon curse seal to varying degrees of success and acclimation.