The Japanese have the Samurai as their unique unit (replacing Swordsman). The advantage is not very big, however. The units are of the same strength, require Civil Service and Machinery to train and receive +50% with melee units. However, in addition Samurai receives 2 first strikes. Not a very serious advantage. By the way, you can’t train Samurai with Copper (Maceman you can); plus Iron is required.
The starting technologies for the Japanese are Fishing and The Wheel. This means that Sailing is available instantly as well as Pottery.
The civilization has only 1 leader – Tokugawa.