Tetsujin 28-gou: Hakuchuu no Zangetsu

A young detective prodigy partners with a massive robot to address a crisis in post-war Tokyo. The story introduces a long-lost sibling of the protagonist, who had been trained to operate a military robot developed by Japan during the war. With peace restored, this character finds little purpose in the changed world. Meanwhile, explosive devices known as "Destruction Bombs" are discovered across the city. These were designed by the protagonist's father, a scientist and the Tetsujin 28 creator, as ultimate defensive weapons. If detonated, the bombs would devastate Tokyo.