From the Imjin War to the Qing Invasion

In order to write an alternate history novel, one must study the respective era.

While setting up the world of the work through studying, I fell asleep and when I woke up, I found myself in the Joseon Dynasty.

Coincidentally, it matched the historical background of the novel I intended to write.

The problem is, it was 10 years before the Imjin War.