An attack on Hawaii did not figure into any official Japanese military plans until 1941. The Navy's initial plan for a hypothetical war against the United States, drafted in 1909 and influenced by the results of the recent Battle of Tsushima, only called for a confrontation with an American fleet close to Japan's shores, where the Japanese Navy would win a decisive battle through a combination of attrition and superior capital ships. This premise formed the basis for subsequent plans conceived over the following three decades.

On the other hand, between 1913 and 1941, a number of Japanese writers and even military officers did anticipate an invasion of Hawaii if hostilities broke out with the United States. These invasion scenarios lay mostly in the realm of fantasy, however. For instance, according to one sequence of events imagined by a retired general in 1921, Japanese forces would destroy the United States Pacific Fleet near Midway, capture Hawaii, land in California, launch air raids upon the Midwest, inspire African-, Jewish-, and German-Americans to rebel against the Anglo-Saxons, embolden Mexico to invade Texas, and finally carry out commando raids in New York City, which would force the Americans to sue for peace.

Incidentally, American military thinkers in the late 1800s and early 1900s feared the possibility of losing Hawaii to a surprise attack by the Japanese, which in fact contributed to the decision to expand the defenses at Pearl Harbor. These fears subsided after 1914, since the opening of the Panama Canal meant that the United States Navy could quickly organize a counteroffensive, whereas the Japanese Navy would need to have enough ships to move the men and supplies necessary for a maintaining an occupation of Hawaii across the entire Pacific. When the question of a potential Japanese invasion came up again in 1928 and 1935, military planners maintained that American submarines and aircraft could easily sink enemy troop transports.

Sources:

David C. Evans and Mark R. Peattie, Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941 (Annapolis: Naval Institute Press, 1997), 129f.

Edward S. Miller, War Plan Orange: The U.S. Strategy to Defeat Japan, 1897-1945 (Annapolis: Naval Institute Press, 1991), 45-47.

John J. Stephan, Hawaii Under the Rising Sun: Japan's Plans for Conquest After Pearl Harbor (Honolulu: University of Hawaii Press, 1984), 59-73.