I second all that has been said about the economic issue.
Currency is needed badly.
If you manage the economic aspect well, Toku is a walk in the park.
Samurais are cool, but somehow short lived.
OTOH, drafting protective and agressive riflemen is really THE thing.
My way to place japan is to go for liberalism ASAP, to get nationalism, then trade my way up in the machinery path to get near to rifling, attack with samurais + cats to get a good number of cities, make sure I have a good globe theater city (= 3 or more food resources) to draft samurais every turn.
From there I beeline too rifling, and as soon as possible start drafting those.
No one will stop you, since japanese rifle draftees start with combat 1, drill 1, CG1.
If you can draft a unit every turn in your GT city and build a catapult every turn in your HE city, you're just too strong to beat.