For centuries, Heaven has required its young angels to live and study among humans in order to become full-fledged angels. This is no different for top-of-her-class Gabriel White Tenma, who believes it is her mission to be a great angel who will bring happiness to mankind. However, Gabriel grows addicted to video games on Earth and eventually becomes a hikikomori. Proclaiming herself a "Fallen Angel," she is apathetic to everything else—much to the annoyance of Vignette April Tsukinose, a demon whom Gabriel befriended in her angelic early days on Earth. Vignette's attempts to revert Gabriel back to her previous self are in vain, as Gabriel shoots down any attempt to change her precious lifestyle. As they spend their time on Earth, they meet two eccentric personalities: the angel Raphiel Ainsworth Shiraha, Gabriel's classmate with a penchant for sadism, and the demon Satanichia McDowell Kurumizawa, a clumsy self-proclaimed future ruler of the Underworld. Gabriel DropOut follows these four friends' comedic lives as they utterly fail to understand what it truly means to be a demon or an angel.

While reveling in the successful clinching of a prized vase for his collection, Yoshifumi Nitta, a yakuza member, is rudely interrupted when a large, peculiar capsule suddenly materializes and falls on his head. He opens the capsule to reveal a young, blue-haired girl, who doesn't divulge anything about herself but her name—Hina—and the fact that she possesses immense powers. As if things couldn't get any worse, she loses control and unleashes an explosion if her powers remain unused. Faced with no other choice, Nitta finds himself becoming her caregiver. To let her use her powers freely, Nitta asks Hina to help out with a construction deal, which goes smoothly. But while this is happening, a rival yakuza group covertly attacks his boss. To Nitta's shock, his colleagues later pin the blame on him! Tasked with attacking the rival group in retaliation, Nitta steels himself and arrives at their hideout. But suddenly, Hina unexpectedly steps in and helps him wipe out the entire group. As it turns out, Hina might just become a valuable asset to Nitta and his yakuza business, provided she does not use her powers on him first! And so the strange life of this unusual duo begins.

During a regular after-school grub crawl, gluttonous high schooler Hibiki Sakura is confronted about her ever-expanding waistline by her best friend, Ayaka Uehara. With her attempts at solitary exercise failing miserably, Hibiki decides to join the newly opened Silverman Gym. At her orientation, Hibiki runs into student council president and school idol Akemi Souryuuin. However, it soon turns out that Hibiki is in for a lot more than she bargained for. Not only is Silverman Gym full of world-renowned bodybuilders and athletes, but to make matters worse, Akemi turns out to be a total muscle fetishist! Grossed out by the scene unfolding before her eyes, Hibiki begins to leave, only to be stopped by trainer Naruzou Machio. Completely enthralled with her newfound Prince Charming, Hibiki signs up as a gym member. Now, as a result of her spur-of-the-moment decision, Hibiki must adapt to her new lifestyle.

It has been five years since AI Kizuna disappeared from the virtual world. Despite being an AI, she has captured the hearts of her fans, including Miracle, an aspiring virtual artist, with her performances. As Miracle attends ADEN Academy, a school for virtual artists, she makes new friends while learning more about singing, performing, and streaming. Miracle's ultimate goal is to win the prestigious Lapin d'Or at the Virtual Grid Awards, an achievement Kizuna has earned five consecutive times. To do this, she works to improve her channel ranking through streams and performances, trying to stand out among other students at the academy. Determined to fulfill her dream of inspiring others the same way Kizuna inspired her, the budding star will not give up.