BasedGod
Chieftain
UU:Samurai
Can build Fishing Boats. Has the sameCombat Strength as Musketman and cannot upgrade to him. Becomes obsolete with Industrialization. Once you research Industrialization Samurai can become following Great Persons: Great Writer, Great Artist, Great Musician, Great Merchant or Great Engineer. But can do so only once. (Same as the Mayan UA, which means you must have 5 Samurai to get each Great Person).
Seems a little dumb that a combat unit that becomes a great person can't become a great general. Also the upgrade cost would have to be pretty damn expensive to balance this out
Also, with this change Japan become pretty much completely vanilla until you hit the unique tech, I know that the Mayan UA is also on a timer (though IIRC it is the only other UA that is) but they get atlatists and pyramids to balance this, both right at the very earlygame. Civs like France for example also have nothing earlygame but for this Japan everything comes at once, from late medieval to industrial they will be extremely strong but they will fall off pretty damn hard midway through the industrial era. This doesn't fit Japan at all, seeing as they are still pretty damn relevant today.