OVA
Description
Kouji Sugimoto, a young Japanese man balancing a part-time mechanic job with engineering studies, leads an ordinary life. His routine shatters when he and his friend Haruo Onose discover a top-secret military cargo accidentally left in Haruo's delivery truck. Haruo, aware of Kouji's engineering background, asks him to inspect the mysterious container. They move it to Kouji's apartment. During this process, Kouji receives a message: his girlfriend, Shiori Nagura, departs for study abroad in England in four days. They plan to meet that evening at the NSR building in Nishi-Shinjuku.

Driven by curiosity, Kouji examines the cargo and its manual. He successfully opens it, revealing the MADOX-01, a prototype powered armor suit designed for anti-tank combat. Kouji enters the suit only to become trapped inside due to a software malfunction. This triggers an alert to the military. Unable to escape, Kouji resolves to reach Shiori before her departure despite his confinement. His attempts to navigate the urban environment in the MADOX-01 draw immediate military pursuit.

Throughout the ordeal, Kouji demonstrates adaptability, gradually learning to operate the suit through trial and error without formal training. His primary motivation remains intensely personal: reaching Shiori to express his feelings before she leaves. This goal anchors him even as military forces escalate their efforts to reclaim the MADOX-01. During confrontations, Kouji consistently avoids lethal force against soldiers, reflecting his civilian nature and aversion to violence. His struggles attract the attention of Eriko "Ellie" Kusumoto, the suit's developer, who provides remote guidance to help him repel attacks.

Lieutenant Kilgore, an American tank commander nursing a personal vendetta against the MADOX-01 stemming from a prior defeat in simulations, independently joins the military recovery operation. Kilgore's aggressive pursuit forces Kouji into a defensive battle. Kouji relies on Ellie's technical support to counter Kilgore's tank assaults within the city. The conflict converges near the NSR building, where Kouji strives to resolve both the immediate military threat and his personal mission involving Shiori.

Kouji's background as a mechanic proves crucial in understanding the MADOX-01's basic functions under pressure. His character arc centers on survival and unwavering determination, fueled by his desire to reconnect with Shiori amidst unintended military escalation.