Extra! Sea Lanes to Australia Cut! Japan Wins Negotiated Peace!
 

Playing as Japan vs. AI, victory in June 1943 -- right as Allied reinforcements really start rolling in!

After playing the first few turns per the manual's tutorial, the Japanese High Command moved to (1) quickly seize the DEI oil field ports (leaving a force of older BBs, cruisers and 1 CV to guard against invasions and raid Ceylon) and (2) seize key SW Pacific bases (Truk, Tarawa, Rabaul, Marianas) and Wake (to provide a buffer against Allied attacks). At the same time, the Striking Force launched repeated raids against the Aleutians, Midway, Pearl Harbor and Palmyra to destroy those bases, forcing the Allies to launch raids/invasions from the West Coast at a substantially reduced CE.

By late 1942, having achieved those goals and having built up Truk into a major base -- and also having destroyed the Sea Lanes bases just for the heck of it -- the Japanese invaded Samoa. After that, the strategy was simple: Base about 80% of the fleet (less the force in the DEI and a small force guarding the Home Islands) at Truk and send them to patrol Samoa. Repeated Allied invasion attempts, launched at CEs of 50-60%, failed. As a back-up plan, and just for fun, the Japanese also captured Espirito Santo, but the base was not operational by the time the war ended after the Sea Lanes had been cut at Samoa for the requisite six months. Banzai!

Notes: The Allied AI seemed timid until the last few months, by which time it was too late -- the IJN had already sunk too many Allied CVs and BBs. Whether due to the Allies' reduced CE, the superiority of Japanse equipment/combat abilities early on, or the luck of the draw, the Japanese fared significantly better in battle than the Allies. I think destroying the bases west of the West Coast -- and keeping them destroyed -- was key to the victory by reducing Allied CEs.

Re: Extra! Sea Lanes to Australia Cut! Japan Wins Negotiated Peace!
 

I was able to win in a similar fashion against the AI after a few tries.
1) First turn, raid Hawaii and take as many bases to the south as possible.
2) Subsequent early turns: use the strike force to take one base per turn until all the oil regions are taken. Use the rest of the carriers to patrol the home islands, waiting for the inevitable Doolittle raid.
3) Use the strike force to expand toward the sea lane islands.
Take at least two bases that can supply a sea lane base (probably E. Santo). This ensures that the Sea Lane base does not get isolated. If you run out of landing fleets, pound Ceylon or Brisbane.
4) Take a Sea Lane base and patrol heavily, waiting for the big counterstrike.

Hopefully game is over before the Essex carriers show up.