When I play Japan I like to play with the long-term in mind. That is, I don’t really go for early do-or-die strategies like an India crush. If I’m given the opportunity, I’ll go for it, but normally I’ll just try to improve Japan’s economy and keep it that way.
On the turn I attack, I grab the Phillipines and as many of the DEI as possible. The rest will be gotten on the next turn. Hong Kong and Malaya are also high-priority objectives. Unless something has gone wrong, getting these will make Japan’s income in around the low-mid 60s, which is perfect.
Then I’ll put 1-2 factories in South East Asia, and just trade Burma with India. With convoying, India can only produce around 1 Infantry a turn, so time is in my favor in that region. I’ll strat bomb the India IC if I ever get the chance.
What determines my success at this point is how much US invested and is continuing to invest in the Pacific. If it’s a majority or all of its resources, I know Japan’s not going to win. I might attack Russia if I see a KJF strat, in order to help Germany win. My fleet builds will primarily be defensive - carriers and destroyers - in order to make my fleet survive as long as possible against the growing US fleet.
If US is only spending some of its income in the Pacific, I’ll be trying to win in the Pacific if possible. After I’ve got my income, I’ll try to place the majority of my fleet in the Carolines. There I can threaten Hawaii and Australia. With luck I’ll try to convoy Australia. I’ll have taken 1 of those four Australian NO islands, so hopefully Anzac’s making less than 10 a turn. With a good Carolines-based threat, Anzac will be building defensively - infantry - for the forseeable future. Thus the majority of my income can go into my trade war against India and for fleet builds to compete with the US fleet. Until India falls, I’ll go mostly for targets of opportunity at this point. Hawaii if possible, but that’s tough. The Pacific Island NO in A3 is impossible, don’t even bother looking at it. The 5/7 NO in A2 was a lot better frankly.
With a long-term strategy like this, Japan’s overall victory threat is maximized.