It does depend on the PoD and what you mean by 'resurgence'. It would seem that Chinese/Japanese 'resurgence' would pretty much rule out Korean resurgence in any meaningful sense (save, I suppose, Korea being able to carve out a trading 'niche' of sorts in SE Asia or in the American Pacific seaboard under Chinese suzerainty).
I suppose if Chinese resurgence happened at around the same time as Japanese resurgence, the chance of Japan leaving China's sphere of influence is comparatively slim, barring a complete Japanese victory over China in the inevitable territorial skirmishes (like over the Ryukyus or maybe Sakhalin). Perhaps this would push the Japanese towards a more trading-oriented policy - alternatively, they might turn their military might away from China and elsewhere in the Pacific, such as the Philippines, the Dutch East Indies, or even Hawaii.
Chinese resurgence likely makes it the 'third' major colonial power in the region after Britain and France. Success at reform may well put an end to the fundamental dilemma of the Manchu minority ruling over a Han majority, with the Manchu getting assimilated into the Chinese identity in the process. The Qing will likely want to re-assert control over various vassal states, starting with Annam, Burma and the like, which would bring it into increasing competition with the UK. The Qing were quick to learn the nuances of international relations after the Opium Wars but with successful modernization one could expect to see the re-emergence of the old Imperial mentality.