Japan yearns to be liberated, only by dragging the US in a big fight with China can Japan have any hopes of a better future. It may seem counter intuitive but a military defeat of Japan (and the US) against the militarily more powerful China is precisely what Japan needs right now. In this context I think the ultranationalist Abe's interests and actions actually align with PRC more, compared to America's loyal dog Kishida, despite Abe's war crime dog whistles. 台湾有事は日本有事 maybe shouldn't be interpreted as Japan's neo-imperial ambitions, but rather like Japan's last plea for help, to save themselves when Taiwan gets liberated. If these Ultranationalist factions succeeds, they would be in some sense a successful version of 曲线救国, perhaps CPC overlords will treat the Japanese better than Uncle Sam's dirty Gaijins.
Also I think Republic of Korea shouldn't be compared with Japan in terms of historical animosity and territorial aggression against China. They (the elites and the masses) can and will switch alliances without much bloodshed, even if they are presently occupied by GIs.
Japan does not yearn to be liberated as you put it.
They're used to American Primacy and being junior (kohai) to the USA.
Currently China isn't sufficiently powerful enough (whether militarily or economically) for Japanese national interest to shift from the US to China.
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In comparison, South Korea has a stark left-right divide because of history.
The conservative, pro-American, right-wing President recently tried a military coup, against the National Assembly and to arrest the opposition party and even members of his own party.
The opposition party (who control National Assembly) was *formed* from the days when South Korea was ruled by a right-wing military dictatorship backed by the Americans.
NB. Notice how the few supporters of the South Korea President keep waving a lot of American flags. But shouldn't they be waving South Korean flags if they are patriots?