Admiral Nippo was a naval officer for Imperial Japan during World War II. By the summer of 1942 his subordinate Captain Nitsu had constructed false submarine periscopes in order to trick American ships into wasting ammunition on false targets. This plot earned the ire of the Sub-Mariner who tracked down Nippo and Nitsu. Posing as a Japanese sailor, Namor attacked them, beating them into submission and turning them over to an American destroyer. There they were forced to witness as the Sub-Mariner used models of American vessels to trick their fleet into destroying itself.