With the Chinese and Mongols, the Japanese are one of the civilizations belonging to the East Asian culture. Their major advantage is their strong infantry. Their unique unit is the Samurai, a speedy infantry unit with extra attack speed.
Guide for Using the Japanese
The Japanese overall are a balanced civ, their fishing ships get 2x hit points and +2P armor and the work rate overall increases by 5% in Dark age, 10% in Feudal, 15% in castle and 20% in Imperial. As well as that, their mill and lumber/mining camps cost 50% less.
This is the kind of race which you can end the game two ways.
1. By building up as many troops as you can in dark age, then advancing to Feudal Age, where your infantry gain 25% attack speed(which when applied to a mass of infantry)which will help you overwhelm most other civs.
2. Save your food and strength till late game, while making sure when you reach castle age you have at least 650 stone, but don't spend too much time trying to get it. The second you hit castle age, you want to have your castle out and pumping out(samurai are very fast at being produced) you super cheap and mega strong samurai and from there, you also get trebuchets, because they pack and unpack and fire fast which makes them formidable in siege as they can be up and firing before anything can destroy them, and are easily overlooked by ALL guides. The reason why I say that you need to wait till late game(castle age) is because only in the late game will other civ's more heavily depend on their special units, and this is where the samurai excel,they have bonus attack damage against ALL special units as well as an unmatched movement speed(apart from Mayans Plumed Archers) so can close down on targets fast while avoiding siege fire. Also the samurai receive the 25% attack speed bonus to their already fast attack speed. With at least 2 legions of samurai and 4-6 trebuchets, you can quite easily besiege most fortresses.
As well as this the Japanese have the access to ALL(non special) ships at the docks. This makes them kings of the sea due to their unbeatable variety of ships and upgrades. As well as galleys having a increase of 50% line of sight.
They lack, camels and paladins, as well as not having blood lines, which means their cavalry has the underhand in most fights. But this does not mean you cannot fight against them. As your halberdier also has a bonus 25% attack speed, which makes them slaughter most cavalry. They also lack bombard towers which makes them weak when defending, and lack siege onager and ram and bombard cannon.
They also lack hoardings which means their castles are weaker, as well as not having architecture which means they have less armor and health, so you really always want to be on the offence as they lack the capability to be defensive.
They also don't have treadmill or heated shot, but that is ok as you will rely on your castles to supply units(and you shouldn't want to lose any) and your ships should rule the sea, so there is no need for castles to have bonus damage to ships.
They also lack shaft mining, so you will need extra villagers to help with mining of stone and gold(you must have gold).