Adaption of Ryō Suzukaze's light novel series of the same name.

The story takes place before Hajime Isayama's original manga and follows Anheru, a member of the Survey Corps who works in weapons development. Anheru is tired of seeing the corpses of his fellow Survey Corps members, and is working to design equipment that will allow humans to be able to kill Titans. Thus far, no one has been able to find out the weak point of the Titans, and so no one has managed to kill one. However, government conservatives think that fighting against Titans is unnecessary, and order the dissolution of the Survey Corps.

(Source: ANN)