Lo slipped beneath the waves, the first victim of the terrifying new Japanese tactic of Kamikaze. But perhaps the strangest and least-known of Japan’s last-ditch defence units were the Fukuryu, or suicide frogmen. In the lead-up to an invasion the Fukuryu would live in special underwater bunkers from which they could emerge undetected to attack enemy ships. On that “volunteer” front, as with kamikaze pilots, the official story of droves of patriotic citizens clamoring to sign up and the reality may have been slightly different. The maiale was designed to attack ships at anchor and would be carried close to the target and launched by a larger conventional submarine.