Equipped with cutting-edge weaponry and specialized troops, a private military organization named Mithril strives to extinguish the world's terrorism and all threats to peace on earth. The organization is powered by the "Whispered," individuals who possess intuitive knowledge and the remarkable ability to create powerful devices and machinery. Seventeen-year-old Sousuke Sagara, a sergeant working for Mithril, has been assigned to protect Kaname Chidori, a Whispered candidate. He is ordered to join her high school class and be as close to her as possible to prevent her from falling into enemy hands—that is, if he can safely blend in with their fellow classmates without revealing his true identity. Sousuke, who was raised on a battlefield and has very little knowledge of an average high school student's lifestyle, must adapt to a normal school life to safeguard Kaname. However, enemy forces have already begun making their move, and Sousuke is about to find out that the adversary coming for the Whispered girl may be a lot more familiar than he expects. [Written by MAL Rewrite]

During a Literature Club meeting, the four club members—along with their faculty adviser's niece—suddenly find themselves with supernatural powers. Now capable of fabricating black flames, resident chuunibyou Jurai Andou is the most ecstatic about their new abilities; unfortunately, his own is only for show and unable to accomplish anything of substance. Moreover, he is completely outclassed by those around him: fellow club member Tomoyo Kanzaki manipulates time, Jurai's childhood friend Hatoko Kushikawa wields control over the five elements, club president Sayumi Takanashi can repair both inanimate objects and living things, and their adviser's niece Chifuyu Himeki is able to create objects out of thin air. However, while the mystery of why they received these powers looms overhead, very little has changed for the Literature Club. The everyday lives of these five superpowered students continue on, albeit now tinged with the supernatural. [Written by MAL Rewrite]

The student-filled Academy City is at the forefront of scientific advancement and home to the esper development program. The seven "Level 5" espers are the most powerful in Academy City, and ranked third among them is middle schooler Mikoto Misaka, an electricity manipulator known as "The Railgun." When strange incidents begin occurring throughout the city, she finds each crime to be connected to the elusive "Level Upper," a legendary device that allegedly increases the esper level of its user. As the situation escalates, it becomes apparent that there is more to the Level Upper than meets the eye, and that Academy City may be a far more twisted place than the glamorous utopia it appears to be. Toaru Kagaku no Railgun focuses on Mikoto and her friends—and the dangerous situations they find themselves in—as they get caught up in the matter of the Level Upper. As Mikoto says, "There's never a dull moment in this city."

Deep in the Ararat Mountains of Turkey, a secret organization known as ARCAM has found what is believed to be Noah's Ark. However, the U.S. Machine Corps., a rogue organization of the Pentagon, wants to take over the Ark as a means of global supremacy. Only a special ARCAM operative known as a Spriggan stands in their way. Japanese Spriggan Yu Ominae teams up with French Spriggan Jean-Jacques Mondo to combat members of the U.S. Machine Corps. led by Col. MacDougall—a genetically-enhanced boy with deadly psionic powers. However, they must act fast and stop MacDougall before he uses the Ark for his own agenda.