Ten months after the Colossal Titan breached the outer wall, humanity has retreated behind the middle wall, having lost vast farmlands and facing a severe food shortage. The Survey Corps struggles to develop effective countermeasures against the Titans, with failed expeditions only wasting lives and resources. It is in this desperate setting that the web series Shingeki no Kyojin: Hangeki no Noroshi unfolds three distinct character-driven stories that bridge the gap between the live-action films Attack on Titan and Attack on Titan: End of the World.

The first arc centers on Hange Zoë, the eccentric Titan research specialist played by Satomi Ishihara. Operating from a secret laboratory, Hange conducts unauthorized experiments on Titans, having successfully captured a living specimen. Izuru, an officer sent from the Security Control Bureau portrayed by Yuta Hiraoka, grows curious about Hanges work and infiltrates her lab. There he discovers the captured Titan, forcing both characters to confront the ethical boundaries and practical necessities of studying humanitys greatest threat. This storyline explores the creation of the Three Dimensional Maneuver Gear within the films continuity while showcasing Hanges unorthodox methods and obsessive curiosity about Titan biology.

The second episode follows Sasha, a bow and arrow specialist played by Nanami Sakuraba, who once hunted with her village people to survive. After a Titan attack destroys her home and scatters her community, Sasha loses her parents and is sent to live with her uncle. To reduce the burden on her relatives, she joins the Survey Corps as a new recruit. The narrative follows her rigorous daily training and her struggle to adapt to military life. One night, the appearance of a suspicious boy triggers a series of strange incidents that challenge Sashas understanding of her new world and force her to confront her past.

The final arc focuses on two exceptional cadets among the new recruits: Fukushi and Lil. Lil, portrayed by Rina Takeda, lost her parents to Titans and channels that trauma into relentless training, determined to become the strongest soldier capable of avenging her family. Fukushi, played by Shu Watanabe, becomes drawn to Lils fierce determination, though his romantic feelings go unreturned. As they endure the harsh days at the training facility together, both struggle with their growing emotions. When their feelings finally surface, a fierce battle develops that tests their combat skills and their personal resolve, ultimately playing a role in launching the counterattack that could change humanitys fate. These three intersecting narratives reveal the everyday lives, secrets, and sacrifices of the soldiers fighting behind the walls, showing how personal struggles and scientific discovery combine to create the weapons and warriors needed for humanitys desperate stand against the Titans.