A sequel to the popular "The School of Spies", this film continues the adventures of one of the graduates who is assigned to crack a powerful spy ring working out of Kobe. Various people are suspected but, finally, it seems that an Army captain and his geisha friend might lead them to the ring.

The last film in the series brings the tale to the doorstep of Pacific War, with the planning of the bombing of Pearl Harbor dominant in Nakano Spy School.

In late 1940 the Japanese were anxious to conclude peace in China and to that end sent Colonel Hidaka to inaugurate negotiations. He was mysteriously assassinated, however, when his car was blown up. The General Staff Headquarters in Japan, sends Lieutenant Shiina, a graduate of the famed Nakano School of Spies inaugurated by Colonel Kusanagi, to investigate the matter. Arriving in Shanghai, he disguises himself as a Chinese coolie and sets out to watch for developments, the only clue being a silver dollar found beside what was left of the victim.