Gekokujo is a mod for Mount and Blade Warband set in the Sengoku period of Japan. The name is a term often translated as "the low-ranked taking over from the high" and was chosen because it was a running theme during that era: Oda Nobunaga descended from a clan of deputies to the nominal governor of their province, but the Oda usurped them and toppled their neighbors; Toyotomi Hideyoshi began his career as a cook and sandal bearer and ended up the ruler of Japan; Tokugawa Ieyasu was an upstart who probably fabricated a claim of descent from the Minamoto clan--the only ones allowed to be granted the title of Shogun. As a player of Gekokujo, you will start from nothing and attempt to gain control of the entire country, making the title fitting.
Gekokujo, in a nutshell, is a labor of love that, while it still has flaws, is certainly one of those mods that every M&B fan should have, or at the very least should try if they get bored of playing with knights and vikings and the sort.
Gekokujo is a very impressive mod that not only provides a refreshing take of the old M&B formula, it also adds a few neat ideas that make the game more fun and balanced, and thus more satisfying.
While it does have a lack of unit variety and there are a few odd bugs here and there, for the most part the good easily overwhelms the bad, such as the lovely soundtrack, massive map, attention to detail and, well.. I can't fit it all, let's just say that. The number of problems I know of I can count on one hand, while all the good things I need both my hands, and maybe even a foot or two.
Really, if you are tired of Native, but still want to swing a sword around, give this a try. It's totally worth it.