Before you do anything else, grab your 6 Axemen in the Hyuga base and run to the SE. If you hesitate for even a few seconds, these troops will simply die, without accomplishing anything. Axemen have essentially no value in the Iron Age, but maybe you can find a use for them later. Assign a control group. Next, jump to your Cavalry. Send them all towards the Hyuga base, assign a control group, and produce one Scout and then a second one. Forage with three villagers. Collect wood with three villagers and produce one more. The remaining three villagers can just stand around for now. Assign two control groups to your swordsmen and two to your archers. If you have some breathing room, you can do a bit of exploration with your archers. You will find some gold near your Town Centre, and a lot of stone in the west corner of your base. Collect stone with two villagers, and allocate any others as the situation demands. You want to have about 15 villagers in this scenario.
You will note that the Hyuga have a fair number of soldiers standing around, and quite a few buildings. They are unlikely to be wiped out anytime soon. Therefore your first Scout should explore your area, and the second one can head to the Hyuga base. Your base is well protected by a forest. There are only two gaps. Wall off the NE one completely, and this needs to happen soon. Don't build any Towers there, because enemy siege weapons will simply blow them away if they so choose. You will have to defend this wall primarily with archers and villagers. Partially wall off the gap facing the Hyuga, leaving a 2-space hole according to standard principles. Build some Towers there as stone becomes available.
When your cavalry arrives in the Hyuga base, you know that the path to your base is clear. Send your Axemen back home. They can stand around in the back and take on any enemy light troops that break through your main forces. Check the Achievements frequently to see how the Hyuga are holding up. If they seem to be taking a beating, send a cavalry sweep through their base and do what you can to help.
Try to maintain a cavalry force in the Hyuga base. Kyushu may or may not permit this. The fact is, if Kyushu decides to mount a major offensive against the Hyuga, there is nothing that you can do about it at this time, because you only have a few units that can meet Kyushu in the open field. You should be able to handle anything that Kyushu throws at your own base, primarily because you have walls and a lot of good foot archers there.
You don't have Coinage yet, and you would like to research it before you mine any gold. However, you are probably going to need a priest right away, so you will have to collect 25 gold before you can afford Coinage. You are not allowed to get Writing, which is unfortunate, because this is one of the rare scenarios where it is actually useful.
As resources come in, you should produce units according to the following schedule, and there really is no room for deviation: villager, 2 x Scouts, 5 x villagers, priest, 2 x horse archers, 2 x heavy infantry, priest, catapult. This puts you at 50 population, and you don't really have a lot of high-tech units. All 14 of your Barracks infantry are essentially useless. You could still win the scenario with what you have, but it is a lot easier if you disband your Barracks infantry and get better units.
Concentrate on protecting your own territory, but if Hyuga is crippled, send them some resources so they can rebuild. Don't be surprised, however, if they just produce some weak units and send them on suicide missions.
By the time you are ready to start disbanding units, Kyushu should be seriously depleted, and you will be ready to start raiding them and hunting down their villagers. Of course, the reason they are depleted is because you mowed them down in heaps at your walls. This required a lot of micromanagement. Now it is time to explore the map. There are three significant features on the map. There is a huge gold deposit in the middle of the map, guarded by two Kyushu Towers. There is a large stone deposit in the Hyuga base which they will probably never use. You probably won't need it either. The Kyushu base is in the NE and is heavily fortified.
When you get the chance, send a cavalry sweep through the Kyushu base. They don't have Ballistics, so you can run right past their Towers. Kill a bunch of villagers and retreat. Heal your troops, and then send your catapult, escorted by your cavalry, to blow up the Kyushu Towers in the middle. Fortify the area and start sucking in the gold.
If you haven't done so yet, disband your Barracks infantry and get some better troops. After all, you don't often get to bathe in gold, so you might as well enjoy the experience. Then go and smash the Kyushu base. Your catapults don't outrange the Kyushu Guard Towers, but 4 Centurions will take one of them down pretty quick.