Fleet building (Axis)
Battleships (70 points or so)
The Yamato (70 points) and Musashi (66 points) give you the most brute power of any ships in the game. They're a little weaker at anti-air than the Iowa. Also they only have extended range 4, instead of extended range 5 for the Iowa. Nevertheless these ships are an outstanding way to provide surface combat power.
Battleships (50 - 55 points)
You have some good options here, including Japan's Nagato, Germany's Bismarck, and Italy's Vittorio Veneto. Ships at this price point generally have extended range 4. Good overall stats, making them strong at surface combat.
Battleships (40 - 45 points)
As with Allied battleships, Axis battleships at this price point tend to decline a bit in power, as compared to their more expensive counterparts. Weaker armor, making it easier to score hits on them. Weaker main guns, making it more difficult for them to penetrate the armor of the game's heaviest units. But you're still looking at powerful units here.
Battleships (below 40 points)
Some interesting Japanese options here, as well as some battleships which aren't Japanese. The things I wrote about the Allied battleships at this price point apply also to Axis battleships.
Cruisers
Japan has some interesting options for cruisers, especially considering the long range of their torpedoes. Torpedoes ignore armor, allowing them to inflict damage on any surface ship. However, cruisers are more vulnerable to surface guns than are battleships. In fact, cruisers are more vulnerable in general than are battleships.
Destroyers
Axis destroyers are broadly similar to their Allied counterparts.
Aircraft carriers
Japan has some very good options with respect to its aircraft carriers. While its carriers apply various types of bonuses, they are especially good at providing bonuses to torpedo bombers. Or, you might choose a slightly less expensive carrier which provides fewer bonuses.
Aircraft
Assuming a cutoff date of 1942 or earlier, the Zero is a reasonably powerful fighter, at a good price. The Val is a good option as a dive bomber. But where Japan shines is the Kate: an excellent torpedo bomber. Not only is the Kate good at attacking heavily armored ships, it can also provide anti-sub war if that's something you need. Considering the bonuses Japanese carriers often provide to torpedo bombers, it's as though you're being warmly encouraged to build at least some Kates. Not that there's anything wrong with including some Val dive bombers into your unit mix. As for patrol bombers: you have some good Japanese options, such as the Betty. Also some good non-Japanese options, like the German Kondor.
Subs
Japanese subs are often a bit more powerful than their American counterparts. But, their price point reflects that.
