Despite endless research, the human mind remains a mystery to this day. Unknown to the public, there exist special individuals who are able to dive deep into the minds of people and even manipulate their memories. Gifted with this ability, Hiroki, Tsukasa, and Satoru are among those who use their power to commit crime under the orders of their leader, Katsuragi. The three step into the dangerous territory of the human mind in order to destroy their assigned targets while striving to keep their own minds and memories safe. [Written by MAL Rewrite]

Six months have passed since the victorious Battle of Britannia and the reclamation of Gallia from Neuroi invaders. Yoshika Miyafuji, member of the famed 501st Joint Fighter Wing, has come back home to Fuso and graduated from middle school. However, her fight is far from over. She receives a letter supposedly sent by her long-deceased father, containing blueprints of a state-of-the-art Striker Unit he had been working on before his death. The Unit, designed specifically for Yoshika, might be capable of harnessing her extraordinary magical powers. Meanwhile, a new threat in Europe is rising. A Neuroi nest of an unprecedented size and might has appeared over Venezia, wiping out local Witch forces and instantly swallowing the northern part of the country. To make matters worse, a newly spotted humanoid type of Neuroi is attempting to come into contact with humans. Yoshika, incapable of abandoning her friends on the front lines, must once again venture to the war-torn continent. [Written by MAL Rewrite]

Miya Tachibana, assuming her annoying brother Junichi will be unlucky in love and alone forever, decides to spy on him at school after hearing that some of her friends find him to be kind and caring. Through her spying, she learns that he gets along well with girls at school, which results in an even bigger misunderstanding, as Miya wrongfully assumes he likes men since he doesn't have a girlfriend. However, after she herself rejects a boy, Miya starts questioning how she views Junichi as she is reminded of Junichi's similar experience from two years earlier. [Written by MAL Rewrite]

Thirteen girls, each with the ability to materialize "Elements" and summon metallic guardians called "Childs" have been brought to Fuuka Academy to battle mysterious creatures called Orphans. Each with a different personality and background, they must decide who they truly care about and why they fight.