There are 9 things to remember about the Japanese Settlements
1 Stuff needed to be efficient , Goods , coins and supplies (more on this later)
2 Get the merchant open as soon as possible , this is your first milestone and a biggy
3 Get to your Shinto Shrines , it will be your primary cuban maker the whole game
4 Remember the quests and try to set up more than 1 quest to be completed at a time. The quests are always the same and in the same order.
5 Do not move stuff around , demolish what isn't needed and only build what is (reason for coins and supplies and a huge time saver)
6 Max out each expansion at 19 and 19 only , less and you are inefficient , more and you waste Japanese goods for nothing
7 Map out your expansions and try to get straight lines with no obstructions for as far as possible (double line is better).
8 Pop buildings keep the population given if disconnected just not the coins. Ram them into a tight space with no roads to maximize the free space
8B Replace huts as soon as possible with the next pop building in line, they are tons more efficient
9 NEVER sell any main building level , you will only get one shot at completing it.