This is a very odd scenario. You begin unable to control any of your female characters, who go around the town looking for you. The Aniki (Builders) are also back... but they're disguised as you!

All of the groups, save the Aniki, can be persuaded to join you, by getting near to them and answering the question that they ask. The Aniki can do this too, and so watch your female companions go against you to begin with. I don't know if the questions asked are random, and I couldn't translate them, but the second answer for Claret and Brenda, and the first answer for Marie seem to get them on your side.

Now, attack the Aniki, and kill them. They will then lose the disguises, and they will gain some troops - Uninin. And they're ~ very ~ tough. They vary depending on the group leader, but I haven't been able to take out one single Uninin unit, so I took out the Aniki instead, which seems a lot easier.

It's worth noting that the Uninin are up for sale. Take Marie to the shop with the white 50P sign outside, and on the turn after she arrives there, teh shopkeeper will ask her first which unit she wishes to buy, and then for whom. I don't know what the names mean, but when asked who you give the unit to, the fourth (bottom) option is to see the rest of the names.