Korea is... content enough, I suppose. There's still a lot of pull for independence, but the relatively low-levels of oppression by the Japanese, and the expansion of Japanese markets to allow for Korean capitalist ventures has made Seoul's relationship to Tokyo far less contentious. Many of the political conservative folks have stepped off the gas pedal for independence as a result.
Is there any chance of the Japanese government moving their capital from Tokyo to Seoul? (I guess Seoul would be renamed Saikyo if this happened).
The Japanese capital moved around quite a lot in history, and I see no obvious reason why it couldn't move again.