For centuries, Heaven has mandated that its young angels live and study among humans to become full-fledged angels. This rule applies equally to Gabriel White Tenma, who tops her class and believes her mission is to become a great angel that brings happiness to mankind. However, Gabriel becomes addicted to video games on Earth and eventually turns into a hikikomori. Declaring herself a "Fallen Angel," she shows apathy toward everything else, which greatly annoys Vignette April Tsukinose, a demon Gabriel befriended during her early days on Earth. Vignette's efforts to restore Gabriel to her former self are futile, as Gabriel rejects any attempt to alter her cherished lifestyle. While spending time on Earth, they encounter two eccentric individuals: Raphiel Ainsworth Shiraha, an angel and Gabriel's classmate with a penchant for sadism, and Satanichia McDowell Kurumizawa, a clumsy demon who claims to be the future ruler of the Underworld. Gabriel DropOut follows the comedic lives of these four friends as they completely fail to understand what it truly means to be a demon or an angel.