Raizō Tanaka was a rear admiral in the Imperial Japanese Navy (IJN) during most of World War II. A specialist in the heavy torpedoes that were carried by all the destroyers and cruisers of the IJN, Tanaka mainly commanded destroyer squadrons, with a cruiser or two attached, and he was the primary leader of the "Tokyo Express" reinforcement and resupply shipments during the long campaign for the island of Guadalcanal in the Solomon Islands of the South Pacific Ocean. From the Americans, Tanaka acquired the nickname of "Tenacious Tanaka" for his stalwart opposition.

The Tokyo Express was the name given by Allied forces to the use of Imperial Japanese Navy ships at night to deliver personnel, supplies, and equipment to Japanese forces operating in and around New Guinea and the Solomon Islands during the Pacific campaign of World War II. The operation involved loading personnel or supplies aboard fast warships, later submarines, and using the warships' speed to deliver the personnel or supplies to the desired location and return to the originating base all within one night so Allied aircraft could not intercept them by day.