The film revolves around a traffic accident that occurred in the back alley of the Neustia embassy in Japan. The body of a socialite is found in one of the cars involved in the accident. Prosecutor Kohei Kuryu and his paralegal Chika Asagi are tasked to pursue the truth and seek redress for the victim. During the course of their investigation, Maiko Amamiya, who is Kuryu’s previous paralegal, makes a surprise appearance as a prosecutor for the Osaka Namba District. As it turns out, the key witness of her threaten case also happens to be the female victim of the Neustia embassy car accident. This seemingly innocuous traffic accident takes a more complicated turn, as new information from Amamiya’s threaten case is brought to the table. Kuryu’s countless requests for information and attempts to interview the embassy staff were all rejected, because the embassy’s territory is regarded as a “foreign space in the land of Japan”. The embassy retains its own laws and rights from its home country, and it seems impossible to interfere with the diplomatic ties between Japan and Neustia.

In such difficult circumstances, how will HERO Kohei Kuryu overcome all odds to put justice in its rightful place?