Toaru Kagaku no Accelerator  

A Certain Scientific Accelerator, Toaru Kagaku no Ippoutsuukou, とある科学の一方通行[アクセラレータ], 某科学的一方通行, To Aru Majutsu no Index Gaiden, とある科学の一方通行〈アクセラレータ〉, 科学一方通行

The city of Academy is a leader in scientific and technological advancements, particularly known for its development of espers who possess supernatural abilities that manipulate reality's rules. Among these powerful individuals are Level 5s, with Accelerator being the most renowned, even after sustaining a severe brain injury. Despite his cold demeanor, he is fiercely protective of Last Order, a young girl whom he vows to safeguard at all costs. Although Accelerator is recovering from his injury, Academy City's dark side remains active, and he finds himself entangled in a new conflict. A mysterious woman pursues Last Order, leading Accelerator to confront an insidious organization that has taken root within Anti-Skill, the city's peacekeeping agency. With dangerous forces at play that threaten to endanger Last Order and her sisters, the self-proclaimed villain prepares to step back into the shadows once more.