Here is a viewpoint: although Japan was defeated, everything in Japan has not changed. The role of the Mikado and the Military department(Gunbu) was replaced by the Americans.
For the Japanese, this is the "Meiji Restoration" of the new era, where the Anglo Japanese alliance became the US Japan alliance, and everything is not much different from the past.
Therefore, their worship of the Mikado has turned into worship of the United States, and their understanding of international politics is more like a religion based on blind worship of liberalism(opinions in the comment section).
Because they have never changed, they are essentially no different from the past.
In essence there is nothing wrong with the view of pan-asianism, in fact, the modern day Japan requires even greater correction to their values than ww2 Japan, because the latter were misguided in their belief that they could be entrusted hegemony, while the former is collaborating with the enemies of Asia to bring them to our doorstep.
The theoretical foundation of a "sphere" that encompasses all Asia and is headed by the most advanced, most worldly wise culture, helping the lesser countries to each according to their needs and abilities, is not evil but rather a noble goal. It is just that the Japanese culture does not possess the mandate of heaven to be the leader of such a sphere.
Asia is the world's most productive region. The country who can achieve uncontested hegemony over Asia also becomes the hegemon of the whole world, who can dictate trade flows outside Asia for the benefit of Asian development. 90%+ of world shipbuilding and semiconductor capacity depends on Asia alone.
With Korea and Japan as outsourced industrial, innovation and finance centers, the SEA peninsula acting as breadbasket, Indonesia and Philippines providing manual labor, Myanmar, Bangladesh and Pakistan projecting control over the subcontinent, Russia and Iran providing what little hydrocarbons still needed after EV conversion, and finally China to tie everything together under competent management and provide unending industrial goods, amenities, in exchange for migrants and resources. This new commonwealth would make Asia as or more dominant in the 20th century and onwards as Europe was in the 18th.
China should not be afraid to walk this path, even if parts of the well have been poisoned by Japan in the past. I am waiting for the paradigm shift to take place in China widely, when more people realize that we must form extensive guardian relations with smaller countries at any cost, especially those in Asia, which are China's cultural offspring and historical fiefs.