The "Noblesse" Cadis Etrama di Raizel, also known as "Rai," is enrolled in Ye Ran High School by his servant Frankenstein to stay hidden from the sights of the Union, a mysterious organization out for Rai's blood. Rai commences his life as a student, making himself familiar with his classmates and the daily activities of humans. However, his new life is far from peaceful, and Rai is soon forced to save his new friends from the hands of the Union that had abducted them. Meanwhile, M-21—a Union agent gone rogue during Rai's rescue operation—joins the Ye Ran High School security staff after a proposition by the school's director, who happens to be none other than Frankenstein himself. On the surface, M-21 is a prim and proper employee, but in truth he is shackled by his former ties to the Union and the inevitable consequences of betraying the organization. To further complicate matters, Nobles Regis K. Landegre and Seira J. Loyard enroll in the same school to investigate the Noblesse. While the Union conducts a manhunt for M-21 to extract clues regarding their missing agents, Rai is forced to keep his identity hidden while protecting all that he holds dear. [Written by MAL Rewrite]

Second-year high school student Yatora Yaguchi is a delinquent with excellent grades, but is unmotivated to find his true calling in life. Yatora spends his days working hard to maintain his academic standing while hanging out with his equally unambitious friends. However, beneath his carefree demeanor, Yatora does not enjoy either activity and wishes he could find something more fulfilling. While mulling over his predicament, Yatora finds himself staring at a vibrant landscape of Shibuya. Unable to express how he feels about the unusually breathtaking sight, he picks up a paintbrush, hoping his thoughts will be conveyed on canvas. After receiving praise for his work, the joy he feels sends him on a journey to enter the extremely competitive Tokyo University of the Arts—a school that only accepts one in every two hundred applicants. Facing talented peers, a lack of understanding of the fine arts, and struggles to obtain his parents’ approval, Yatora is confronted by much adversity. In the hopes of securing one of the five prestigious spots in his program of choice, Yatora must show that his inexperience does not define him.

At True Cross Academy, Rin Okumura unknowingly comes across the first signs that something is amiss; ordinary people have been gaining the ability to perceive the invisible creatures that roam the human realm, Assiah. While Rin sees this as an opportunity to make a new friend, his twin brother, Yukio, is more burdened than ever. Swamped with his education, exorcist duties, and teaching position, Yukio has remained silent about his awakened powers, unable to understand their scale or significance. While Rin and his friends prepare for the annual Exorcist Certification Exam, the True Cross Order has uncovered the first artificial gate to the demonic realm of Gehenna. Witnessing its size and the advanced technology that made it possible, the exorcists realize they are now dealing with the Illuminati, an extremely wealthy and powerful organization. Moreover, the inscrutable Illuminati have planted three spies in the True Cross Order—and one may be hiding among the aspiring exorcists sworn to protect mankind from the demonic threat.

When a gate to another world suddenly opens on Earth, Mikado City is invaded by strange creatures known as "Neighbors," malicious beings impervious to traditional weaponry. In response to their arrival, an organization called the Border Defense Agency has been established to combat the Neighbor menace through special weapons called "Triggers." Even though several years have passed after the gate first opened, Neighbors are still a threat and members of Border remain on guard to ensure the safety of the planet. Despite this delicate situation, members-in-training, such as Osamu Mikumo, are not permitted to use their Triggers outside of headquarters. But when the mysterious new student in his class is dragged into a forbidden area by bullies, they are attacked by Neighbors, and Osamu has no choice but to do what he believes is right. Much to his surprise, however, the transfer student Yuuma Kuga makes short work of the aliens, revealing that he is a humanoid Neighbor in disguise. [Written by MAL Rewrite]