After graduating from a top university with an impressive extracurricular record in the rugby club, Akira Tendou has nailed every step of the way to securing his dream job. On top of that, a beautiful and kind co-worker always brightens his day in the office! Life seems to be going very well for Akira until he slowly realizes that sleepless nights and brutal work are his new reality. Due to three years of mind-numbing labor in an exploitative company, Akira is unable to recognize the tired, unaccomplished person he has become. On track to losing all passion in life like several of his overworked colleagues, Akira finds his saving grace in the most unexpected way possible—the breakout of a zombie apocalypse. With the free time he finally has, Akira decides to complete a bucket list of a hundred things he wants to do before he eventually gets turned into a zombie. Although he is surrounded by the dead, Akira has never felt more alive!

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.

In the near future, 10 percent of the population will consist of Humanoids—machines with advanced functions and artificial intelligence resembling human personalities, easily recognized by their sideways pupils. These specialized patients likewise require a special doctor. By day, Dr. Hikaru Sudou runs a medical clinic for Humanoids; by night, under the moniker of Moggadeet, he performs illegal procedures and gathers information about his lost mother. Hikaru encounters patients with varying problems unique to this society: a Humanoid struggling with the question of whether she and the source of her backup data are the same person, a teenage Humanoid who cannot improve athletically, and even a robot teddy bear with memories of multiple owners. As the world's technology constantly evolves, newer and more complex questions surrounding humanity arise. With each new advance, it becomes more difficult to define what truly makes one human or Humanoid.

During a school trip, a bus full of students is suddenly transported to another world by a sage named Sion. She bestows most of the students with powers called Gifts, seeking to recruit them to become sages as well. However, a few are excluded from receiving a Gift, resulting in the others leaving them behind. Yogiri Takatou, one of the students who did not receive a Gift, wakes up to find a dragon attacking the bus. Amidst the chaos, he executes the dragon using his innate ability to instantly put anything to death. Alongside fellow survivor Tomochika Dannoura, Takatou sets out to find a way back to Earth, all while eliminating anyone who dares to underestimate him—including his former classmates.