How would Modern Day Japan in universe where they get invade by Korea and get turn to Colony instead be like

I just think universe where Nobunaga, Ieyasu & Hideyoshi were never born, and Japan never get unified into one state but they slowly get invaded by the Kingdom of Korea from southern japan slowly to northern japan after they got gun technology from Portugal & China, and developed their own Tagenashima and how modern-day Japanese with more Korean Influence would be like as well as Korean King start to Modernize country by tour Europe early

There's too much questions to ask, when you are talking about a timespan between the late 16th century to modern day, about 4 centuries.
In the short term, such a war would be very costly, and the Korean economy would be in bad shape. If China decided to stay out of the war, it might delay the fall of the Ming dynasty to the Qing.
Another point to think about is whether Korea will keep Japan, or have it as a vassal state. In the latter case, modernization might even be delayed, because Korea's contact with the West was mostly through Qing China. I don't know enough about Chinese history to consider that variable fully. \\That is an unusual alternate history scenario since most Korean alternate history fiction focuses on the late 18th century~early 20th century.

You'd have to work really hard to make it not to come across as Misplaced Nationalism (especially since Japan and both Koreas are still on rough terms).

Secondly it comes across as highly unlikely on the base scenario for a few reasons. 1st and foremost is that historically Korea has not really had any expansionist phases. Secondly a foreign invasion is likely to trigger a unification event behind someone. For earlier settings... Takeda Shingen or Uesegi Kenshin, latter on more likely Date Masemune. Or someone else entirely if the butterfly flaps hard enough.

Finally historical evidence suggests (specifically from Totoyomi Hideyohi's actual invasion of Korea) that after two hundred years fighting each other had given Japan enough battle-hardened troops that once they got organised they would have driven back any Korean invasion force. And it may not have taken that long. By the late Sengonku Jidai power was starting to consolidate again it was more of a question of who would come out on top eventually.

Edited by KnightofLsama on Oct 2nd 2022 at 12:41:02 PM

Thanks

If you want Korea to invade Japan then consider a century or so after the Imjin war. Japan stagnated during the Tokugawa Shogunate and much of their weapons had been destroyed or heavily restrinted. Famously, all the peasant's swords were melted down into a statue of the Buddha. If Korea offered Dutch Sailors a good trade deal in exchange for the latest in European technology they could face Japan with flintlocks and when most of the island had bows and swords. Korea has large coal and iron deposits so they could become a powerhouse by the 1800s.