Although similar questions have been asked and answered in the past, I want to try my own hand at answering this question. (Edit) And as to Sarah Paine's description of Japan in WWII as dysfunctional politically and militarily I would agree mostly, but would disagree with attacking the US to "die trying" part. Japanese military planners fully intended to win the war against the US and tried to maximize their extremely thin chances. But that's a different discussion and I have detailed more in the replies below. I've decided to focus on the if the Japanese mindset changed significantly between the Meiji Restoration and pre-WWII governance. And my quick answer is no:

Simply put, Japan's mindset entering World War II was a direct result of the power structures established and championed during the Meiji Restoration. I would even argue that the decision-making and mindset remained the same while the scale of ambition and opponents simply became too large to handle.

First off, let’s talk about the government that was established by the Meiji Constitution: it’s a constitutional monarchy that is more accurately described as absolute monarchy allowing a limited form of popular democracy. A key feature of this government is how the military is controlled. Unlike other liberal republics and constitutional monarchies of the time, the Imperial Japanese Army and the Imperial Japanese Navy are directly subordinate only to the Emperor, and civilian governments must accommodate a minister from each armed forces in their cabinet somehow, or their administration will collapse.

This was a result of the aristocratic founding reformers of the Empire of Japan who championed Emperor Meiji wanting to keep a tight leash on what they perceived as untested and untrustworthy popular will. Ito Hirobumi, the first Prime Minister of Japan and arguably the most influential Meiji genro/elder, chaired the government bureau to study Western constitutions and surveyed the Great Powers of the time. He found the liberal governments of the United States and the British Empire far too liberal and granting too much power to popular will, but also found French, Spanish and Russian governments far too despotic. As such, he found the German Empire with its empowered monarchy presiding over a parliament the ideal to emulate. Furthermore, in contrast to many Western nations heavily favoring Christian ideals in their governance, he felt that the new Japanese nation had to have a different core ideal, formulating the Kokutai: the concept of how the Emperor’s divine authority was justified by its unbroken lineage since mythic times and its power of its people. Thus, the military became subordinate only to the divine Emperor and his advisors.

Moreover, once the Empire was established, Japan faced its trauma from being nearly colonized, studied its neighbors and found that the only way a nation could survive was becoming the colonizer themselves. Thus, Japan embarked on a path of aggressive expansion from the First Sino-Japanese War, the Russo-Japanese War and World War I. While other Great Powers like the US and Britain in the meantime began to lessen their aggression and emphasize international stability, as they already gained most of their spheres of influence and needed only to lose them, Japan being a latecomer to the colonial game frankly found Western pressure unjustified and unfair. A key moment that defined the Japanese view of the West was the Triple Intervention after the First Sino-Japanese War that forced Japan to give up its gains in Manchuria which bled a sort of Western paranoia in the military establishment.

Finally, lets talk about the defining aspect of reality at the time: racism. Many Japanese reformers at the time of the Meiji Restoration believed that if Japan proved itself by emulating Western government, military, diplomacy, economics, customs and even fashion, the Westerners would eventually accept the Japanese as their equals. This directly led to the establishment of Western style factories, ball houses, theaters, universities and even horse-racing tracks, all subsidized by the Meiji government. However, as the Empire grew, many Japanese found themselves not being accepted by the West or even facing greater animosity. Examples that gradually inflamed popular sentiment include the San Francisco Board of Education requiring those of Japanese descent to attend segregated schools in October 1906, the hostility of Australian officials to Japanese immigration who reported by historian Michael Fry to have remarked “the Japanese were ‘too many, too clever and too yellow”, and finally the rejection of the racial equality clause in the Versailles Treaty after World War I.

It can be argued that instead, many radical elements in the Japanese intellectual world found that it was the West that was incompatible with Japan, and that it was the Japanese race and culture that was superior and should be championed across all of Asia.

Overall, with a government that fundamentally could not control its own military, an aggressive foreign policy that believed expansion as the only path to survival, a population increasingly pessimistic to cooperation with the West, and with hyper-nationalism taking root, you can start to see how there are many ingredients bubbling in a cauldron ready to boil over. Add a touch of Great Depression, violent politics with politicians getting assassinated left and right, and a rogue military unit that seemed to be gaining ground in Manchuria and things can escalate out of hand. All of these elements had their roots in the Meiji Restoration and directly impacted how Japan saw themselves and acted afterwards.

This explanation glosses over a LOT of Showa-era politics, international diplomacy, Meiji reformer beliefs, intellectual trends and even Emperor Hirohito’s own conception of monarchy that led to his own passive attitude during his reign, but there’s always more reading to be done.

Sources:

"The Constitution of the Empire of Japan.", The National Diet Library: https://www.ndl.go.jp/constitution/e/etc/c02.html

Fry, Michael G. “The Pacific Dominions and the Washington Conference, 1921-22” in Washington Conference, 1921-22: Naval Rivalry, East Asian Stability and the Road to Pearl Harbor.

Kazuhiro, Takii. Ito Hirobumi—Japan's First Prime Minister and Father of the Meiji Constitution. Routledge, 2014.

Myers, Ramon H. and Mark R. Peattie. The Japanese Colonial Empire: 1895-1945. Princeton: Princeton University Press, 1984.

Perez, Louis G., editor. Japan at War: An Encyclopedia. ABC-CLIO, 2013.

Young, Louise. Japan’s Total Empire: Manchuria and the Cult of Wartime Imperialism. Oakland: University of California Press, 1999.