A Europa Universalis After Action Report based on the Japanese nation of Uesugi. EU4 is a grand strategy nation-building game that takes place from 1444 to 1821, created by Paradox Interactive, that allows you to play many nations of the time period. For those unfamiliar with the concept of an AAR, it's basically a Let's Play but in text-based form, that's often more story-oriented than gameplay oriented.