Thanks to the Fruit of Evolution, Seiichi Hiiragi's amazing new life in another world allows him to meet dependable allies and create formidable spells. His abilities catch the attention of Barnabus Ablitt, the principal of the Barbador Academy of Magic, who invites Seiichi to become a teacher at the institution. Coincidentally, Seiichi's classmates from Earth are enrolled there, which will lead to an awkward reunion if he is to meet them. Behind the scenes, however, an enigmatic cult called The Great Devil Order devises a sinister scheme to resurrect their deity and sacrifice the students of Barbador to hasten the process. As Seiichi's power is second to none, it is up to him to protect not only his friends but also the entire world from the looming darkness.

A decade ago, mankind witnessed the deadly potential of weapons caused by the Great War. To avoid another catastrophe, governments worldwide have resorted to espionage to fulfill their agendas. In the Din Republic, Lily is an enthusiastic young girl who aspires to become a spy and serve her nation. However, she begins to doubt her abilities, as she struggles to perform well academically. Lily's passion is reignited when she is offered provisional graduation by joining the spy team Lamplight, which she eagerly accepts despite the enigmatic nature of the opportunity. Upon arriving at her destination, Lily is surprised to find six other girls waiting there, all of whom have faced their own academic difficulties as well. A mysterious man named Klaus soon appears and reveals they must complete an "Impossible Mission": to infiltrate the Galgad Empire after just one month of training. Although skeptical, the girls eventually agree to work together under Klaus' guidance—as this might be their only chance to prove their worth as spies.

Childhood friends Tomo Aizawa and Junichirou "Jun" Kubota do everything together, whether it be training or just enjoying a fun day out. Anyone would think that these two are best friends for life. The only issue is that the tomboyish Tomo is in love with Jun, but he regards her like a brother. At the start of their first year of high school, Tomo confesses her feelings to Jun. However, her rough mannerisms and lack of hesitance to throw a punch do nothing to sway Jun's heart. Realizing that he will remain indifferent to her affections unless she does something about it, Tomo must find a way to knock some sense into Jun and open his eyes to what is right in front of him.

Due to rising sea levels and a rapidly declining human population, androids have been engineered to perform most menial tasks, allowing humans to focus on other things. Aside from providing manual labor and customer service, androids also entertain humans through Babel—a tower where participants captivate audiences with song and dance to clear Climb Stages. The higher the climb, the more prize money is awarded. Androids Cobalt, Chrom, Neon, and Kei are down on their luck and about to have their electricity cut off from unpaid bills. Desperate to make a quick buck, the group decide to become Babel climbers. However, winning the audience's favor is a great challenge. Dejected but unwilling to give up, Cobalt resolves to somehow improve their chances after watching an impressive performance by STAND-ALONE—the top climber unit. When the group stumbles across a mysterious choreographer willing to give away his routine, Cobalt sees this as their only way up. With the help of their human companion, Esora Shibaura, the androids form the unit KNoCC to tackle the daunting climb to the top of Babel, but they must also overcome android-based discrimination along the way.