After saving Last Order and subsequently taking a bullet to the head, Academy City's top-ranked esper rests in the hospital. But his recovery is cut short when a mysterious girl carrying a photo of his little clone companion asks for help.

Academy City stands at the forefront of scientific and technological progress, best known for their development of espers: those capable of wielding superhuman abilities that alter the rules of reality. The most powerful among them are the Level 5s, and the one known as Accelerator reigns supreme, even after being weakened by a severe brain injury. By his side is the young girl known as Last Order, whom despite his cold demeanor, he holds closely and vows to protect at all costs. Though Accelerator may be recovering from his injury, the dark side of Academy City never rests, and so he finds himself unwillingly caught up in the midst of a new conflict. When a mysterious young woman approaches Accelerator in pursuit of Last Order, the highest-ranked esper is confronted by a venomous organization that has taken root in Anti-Skill, Academy City's peacekeeping organization. With dangerous forces on the move that threaten to put Last Order and her sisters at risk, the self-proclaimed villain prepares to step into the darkness once again.—MAL Rewrite

Paying the price of losing most of his powers, Accelerator, an esper of the highest rank in Academy City, leads a quiet life in recovery after protecting the young cheerful maiden known as Last Order. Peace ends with rescuing Estelle Rosenthal, a mysterious girl carrying a photo of Last Order. Accelerator finds himself up against a sinister organization called Disciplinary Action, which seeks to capture Last Order and use her for a dangerous plan. The fate of Last Order and Academy City rests in the hands of the ultimate esper and his newfound companion.—Muse Asia

After rescuing Last Order and subsequently taking a bullet to the head, Academy City's top-ranked esper rests in the hospital. But Accelerator's recovery is cut short when a mysterious girl carrying a photo of his little clone companion asks for help. Now they're taking on Disciplinary Action-an anti-evil coalition whose sinister plans threaten Last Order, Academy City, and even the entire world.—Crunchyroll