Frederica Hanashiro from the Ministry of Foreign Affairs visits the Public Safety Bureau to offer Teppei Sugou a chance to clear his criminal record and rejoin the military. Since Sugou was once an ace pilot in the National Defense Army, Frederica gives him this opportunity due to his past as a latent criminal. As he contemplates the proposal, Sugou reflects on his time in the army. During a mission, his First Guardian drone was instructed to drop supplies and leave behind a ground unit-including his commanding officer, Itsuki Ootomo. Despite their disappearance being declared as missing, it was evident that they had marched to their deaths. Three months later, during a massacre at the Ministry of Defense, security cameras captured Ootomo at the scene, making him a suspect in assisting a terrorist attack. Along with Inspector Risa Aoyanagi and Enforcer Tomomi Masaoka, Sugou works to uncover the truth behind this case.