Took a quick look around and saw quite a few infrastructure builds. Thought about changing to Theocracy and changing the builds to units for the war with Toku.
However, after scouting the Japanese island I see that Toku has approximately 3 times as many units on the island as we do. We don't have a big enough tech advantage to overcome that quickly nor do we have enough units to slog through that many (particularly the massive stack at Tokyo).
So, I develop a plan. Build a few more grenadiers and catapults, leave the infrastucture builds where they are, whip a little bit, and wait for rifling and REDCOATS!!!
Now, to help with getting research quickly, I decide to trade Chemistry. I know, it is a bad idea to trade military techs, but Gandhi already has it and the others will be well past it before we attack them, so I got Nationalism and 1020 gold for it. The gold lets me go back up to 80% research, 20% culture (for war weariness). Nationalism will also allow us to draft Redcoats, I believe.
Edo was low hanging fruit, so I used the stacks we have on the island to take it after fighting off some weak counter attacks on Kagoshima. Lost two cats and one grenadier in the fighting.
Looking at this stack led me to believe that we just don't have enough units on the island to take Toku yet.
So, I decided to take all of his upgrade gold.....and go to 100% research once the war weariness went away.
After this, I focused on infrastructure builds while waiting for rifling. Also built a couple of missionaries to spread the faiths and generate some gold. In 1631 we finish replaceable parts and are starting on Rifling.
In 1637, against 80% odds for a Great Prophet, we see this little beauty!!
He will give us most of Steam Power if we want, but I'd save him for the next good wonder that comes along. We still have a Great Prophet in York so we could start a golden age (however, we might need three now), but I don't think I'd recommend that. We might be better off merging the GP in York for the cash.
On my 15th turn, 1655 AD, the peace deal with Toku expires and we are about 3 turns away from rifling. After rifling completes, I would suggest stopping research for about 4 or 5 turns and using the money to upgrade all grenadiers to Redcoats (I hope they will upgrade that way). Also, switch to Theocracy, and Nationalism and spend three turns drafting. I think we draft redcoats, so the army will grow very powerful very quickly. Those bright red jackets should provide the edge to finish off Toku pretty quickly.
After the upgrades, I'd switch to military tradition (should take about 10 turns) for cavalry and then steel for cannon.
Save is attached.