Send all five of your defender cores to the northeast, right when you have control. Place them in a line across the channel to help prevent any units from entering the bay. Your starting subs and tengus should go there as well, to lend a hand. Build two more defender cores at your base in the meantime. Send the two defender cores along with the engineers and other infantry to the north to capture the long range radar tower. Your co-commander should handle the other two. Once they've arrived, place your two extra cores to the east of the northern harbor to protect it from dolphins.

You should make an additional eight yari mini subs and four tengus to help defend the line you've created. Doing this, no ships will be able to enter the harbor. You just need to remain vigilant and reinforce them as often as possible with teh long-term goal of making a massive fleet there. Work your way up to fifteen or more yaris, while making at least ten mecha tengu to be your mobile air support. Later the allies will start sending century bombers, and you need to have a counter.

Order your co-commander to take position whenever a monument is under attack. Your mobile tengus can land to help defend them as well, especially where there are paradrops as to the northwest. Continue to wait out the attacks and increase your unit numbers. Keep your eyes open for bombing runs and cryocopters for your mecha tengus to hunt, this will grant them promotions and help your co-commander to defend. At around 5 minutes till the arrival of your shogun battleships, some naginata cruisers will come to reinforce you. Station them near the northwestern harbor.

Keep your mecha and jet tengus flying to hold off air attacks and eliminate paradrops. At this point I had about twenty yari subs defending the harbor, more than enough for an overkill later. You can stop making yaris at this point and make naginatas back at your dock. Spend as much as you can to keep your navy growing.

As you near three minutes remaining, aircraft carriers will likely start assaulting your base. Order your co-commander to strike them while you do the same. They need to go down fast because they can cause quite a bit of damage from long range and won't trigger an automatic response from your units. Reinforce your defense fleet with naginatas as often as you can.

Your naginatas stationed at the northwestern harbor will eventually see an MCV moving in to set up a base there. Destroy it then bring the naginatas to your main fleet. When the shogun battleships finally arrived, I had about ten naginatas, twenty-six yari mini subs and a plethora of mecha tengus. Set the shogun battleships to their own hotkey group while the rest of your fleet is in another, and move toward the allied base. Move slowly, using the shogun battleships to hammer the spectrum towers and the like from afar. It is not hard at all at this point. Enjoy your crushing victory.