Bulletproof Wall takes you back to Korea in the 1940's under Japanese imperial command. During this period of time Kim II Sung rose to power as the leader of the anti-Japanese guerrillas group in Manchuria to fight off the Japanese and to claim their country back.

The series revolves around Japanese imperialists and Korean spies fighting a spy war in the shadows. The plot consists of numerous life-threatening crises in which the protagonists are often forced to make difficult decisions to save their spy organization.