It was revealed back in October 2018 that A Certain Scientific Accelerator, a spinoff from the overall A Certain Magical Index franchise, was getting an anime adaptation as well with 2019 plans. We knew some of the staffing from then but now the official site has updated to reveal a summer 2019 premiere in July for it with a new minute-long promotional video highlighting it. Nobuharu Kamanaka is on board to direct based on the series composition by Kenji Sugihara. Yohei Yaegashi is handling the character design work with JC Staff producing the animation.
Nobuhiko Okamoto is on board as Accelerator while Rina Hidaka will play Last Order.
Plot concept: Toaru Kagaku no Accelerator, which Accelerator is the main character. The events of the manga occur after his defeat at the hands of Kamijou Touma and the gunshot wound that he received at the hands of Amai Ao, though it is later revealed that the manga takes place prior to meeting Yomikawa Aiho.
— ??????????? (@toaru_project) March 22, 2019