Set in a cyberpunk future (2030), it follows high schooler Akira Natsume, whose brain is saved after a fatal accident and turned into a highly advanced superweapon called an "EX-ARM".
The 2021 anime adaptation by the studio Visual Flight is where the franchise’s reputation shifted dramatically. Ex-Arm (TV Series 2021) - IMDb
It ran in Grand Jump and later on Shōnen Jump+ .
Ex-Arm is a science-fiction series that began as a Japanese manga but became globally infamous for its disastrous 2021 anime adaptation. Originally intended to be a flagship "Crunchyroll Original," the anime is now frequently cited by fans and critics as one of the worst anime ever produced. 📖 The Manga Origins
Written by HiRock and illustrated by Shinya Komi, the manga began in 2015 as a remake of Komi’s earlier work, Ex-Vita .