It is always difficult for me to say "Japan wanted to do so and so". Not all Japanese are or were the same and the policy of one state is resultant from many actors, actions and so forth.
The immediate goals of the Japanese military were definitely focused an the co-prosperity sphere which meant mostly the neighbouring landmasses of Asia. Small and resource lacking islands are only of tactical and strategic value as bases but the Japanese needed resources the most. Therefore the short term interest in Hawaii was surely just knocking out the Americans, ideally denying them the use of the island altogether, possibly even through occupation. But this is of cause speculation in hindsight and it was not really feasible based on the costly nature of such an operation.
But regarding the plans some Japanese policy-makers, doctrine writers, -interpreters or philosophers did have, there was:
Ambiguous in its original context, Tanaka interpreted the statement attributed to Jinmu, as meaning that imperial rule had been divinely ordained to expand until it united the entire world. While Tanaka saw this outcome as resulting from the emperor's moral leadership, many of his followers were less pacifist in their outlook, despite some intellectuals' awareness of the inherent nationalist implications and reactions to this term. Koyama Iwao (1905–93), disciple of Nishida, and drawing of Adornment Sutra Flower, proposed the interpretation "to be included or to find a place". This understanding was rejected by the military circles of the nationalist Right.
That these 'philosophers' include Hawaii with the concept of "entire world" seems as obvious as grandiose. Or insane? Or too lofty and abstract?
Well not really. Military minds always stumble in the footsteps of Alexander:
[…] in a telegram to Foreign Minister Shigenobu Okuma, Hoshi had urged the following course of action: "I submit my plan, which I believe to be the only possible means of frustrating scheme of Hawaiian annexation, that is, our occupation of that Island by dispatching, without any delay some powerful ships under the name of reprisal, taking advantage of present relation between Japan and Hawaii."
Hoshi's advice was not taken by his superiors, but the matter did not end there. One Japanese diplomat, disgusted by his government's weak response to the American action, attempted suicide en route home from Honolulu on the Naniwa.
In the longer run, the obstruction of Japan's peaceful expansion into Hawaii through restrictions to immigration, together with the disappointment of vague but deep rooted expectations for a closer relationship with the Islands, left a residue of frustration. Both the frustration and the expectations were resurrected fortyfour years later when Hawaii suddenly emerged as a strategic target and visionary object in the Greater East Asia War.
––John J. Stephan: "Hawaii Under the Rising Sun. Japan's Plans for Conquest after Pearl Harbor", University of Hawaii Press: Honolulu, 1984, p17–18. –– Note that these lines talk about the turn of the century, not around the time of Pearl Harbor.
These plans however popped up again and again:
In characterizing types of political relationships within the Sphere, the "Draft Outline" proposed four categories: (1) territories to be incorporated into the Japanese Empire; (2) autonomous regions under Japanese protection; (3) independent countries closely tied to Japan by economic and defense agreements; and (4) independent countries linked to Japan by only economic ties. Hawaii and the Philippine island of Mindanao (which had a significant local Japanese population) were to be annexed and treated as Imperial possessions falling into the first category.
Although the "Draft Outline" identified Hawaii as a target for annexation, the Planning Section of the Navy General Staff's First Department paid little attention to the possibility of mounting an invasion of the islands. The 1940 war plan rested upon the same basic assumptions that had governed its predecessors for over ten years: a Japanese-American conflict would be decided by an engagement between battleships after submarines had weakened the advancing American fleet through a strategy of attrition. The only significant innovation of the 1940 plan was that the projected "decisive battle" was moved two thousand miles eastward from the Marianas to the Marshalls.
Within the Combined Fleet, however, Hawaii by 1940 and 1941 was attracting serious interest as both a tactical and a strategic objective. Ironically, this interest derived largely from the commander in chief's awareness of Japan's basic weakness.
By the fall of 1940, Admiral Yamamoto was more certain than ever that Japan could not win a war of attrition with the United States. Japan, in his opinion, could not sustain a drawnout struggle even if it managed to seize the raw materials of Southeast Asia. The Tripartite Alliance, which some younger naval officers hailed as a deterrent against American belligerency in the Pacific, Yamamoto wrote off as a dangerous liability. If Japan could not win a long war, the admiral reasoned, it should not fight the United States. If it were driven to fight the United States, then that war must be a short one. Only in a short conflict could Japan hold its initial advantage. As the commander in chief bluntly told Prime Minister Konoe in September 1940: "If I am told to fight regardless of consequences, I shall run wild for the first six months or a year, but I have utterly no confidence for the second or third years."
One thing seems apparent: while most Japanese arguments at the turn of the century were partially motivated by the large portion of Japanese already on the island, later plans had increasingly less interest in those people, compared to the situation described above.
The presence of a large number of Japanese in Hawaii (160,000 or approximately 40 percent of the population) greatly influenced how planners approached the problem of political control. Ethnic as well as strategic considerations may have underlay the Navy General Staff's categorization of Hawaii as an area to be annexed by Japan (the Staff's 1940 "Draft Outline" of the CoProsperity Sphere). Tsugio Murakami also seems to have leaned toward close cooperation with local Japanese in setting up a local political administration. Estimating that about 70 percent of Hawaii Japanese would "immediately" (sokuza ni) collaborate with occupation forces, Murakami enumerated the advantages of giving priority to ethnic solidarity:
…believing in Japanese religions, having used Japanese as a daily language, and assuming that they will not have been interned and sent away [by the Americans], about 70% of all the Japanese [in Hawaii] will be useful as ready collaborators. Special attention must be accorded to their leadership in the agrarian sector, which will make an enormous contribution to restructuring production, one of the main tasks in building a new Hawaii. We must also thank these people for having been the pioneers of the allpermeating Imperial Way in Hawaii.
Soen Yamashita put the matter of ethnic solidarity succintly in a 1942 book about the islands: "If one speaks of liberation of Hawaii's people, then it is more logical to refer to the Japanese than to the Hawaiians." Yoshi Kanda echoed this sentiment in the assertion that: "For the sake of 150,000 [sic] compatriots, Hawaii must belong to Japan."
Not all planners, however, pinned their hopes only on local Japanese. Colbert Kurokawa, for one, shaped his proposals around native Hawaiians. Hawaii, he felt, should be restored to its earlier role as a meeting ground of various Pacific peoples. Achieving multiracial harmony should be Japan's guiding principle in the occupation. Kurokawa asked: "Is not Imperial Japan's great mission really to build a new Hawaii by liberating the natives and making Hawaii a temple of [multiracial] harmony in a new Pacific age?"
Kurokawa's question is not as whimsical as it at first sounds. Japan had ample experience "restoring" areas to "native" inhabitants. In 1932, having occupied large sections of northeastern China, the Imperial Army set up a multiracial puppet state dubbed "Manchukuo," presided over by an ornamental Manchu emperor who had been whisked out of Tientsin and propped up on a throne to "rule'' for the next thirteen years under the watchful eyes of Japanese advisors. The Imperial Army also set up puppet regimes in Inner Mongolia and North China during the 1930s, using Mongol princes and pliant Chinese generals and politicians to give them a veneer of legitimacy. Analogous measures were being taken in Burma, the Dutch East Indies, and the Philippines as Japanese forces took over former British, Dutch, and American colonies in 1941 and 1942.
In the end the military necessities ruled the day.
Yamamoto was apparently very flexible when considering plans for Hawaii:
According to the recollections of Captain Kuroshima, Yamamoto did not envision a Japanese annexation of Hawaii. Rather, the islands would be used as a bargaining tool to secure a peace treaty that left Japan in control of the western Pacific. Their ultimate disposition would be left up to diplomats and politicians. Annexation was but one of several options, including the establishment of a protectorate, the creation of an independent state, or even retrocession to the United States.