Romancing SaGa 2

I did this on the 4th generation (So Leon > Gerard > Heir 1 > Heir 2), you must reach the Saigos Village which is accessible after completing the Ludon Mines mission which I did a generation or so ago. If you talk to the grandmother in one of the houses in Tefal she will mention a lake further away which opens up the Ludon Highlands on the map (it's not obvious on the map but it's a flat area in the mountains to the left of Tefal), here if you enter this area and head south you can find Saigos Village.

Here I talked to the man at the south of the village who mentioned some troubles nearby which opened up East Oubliette. After completing that dungeon I headed back to the village and spoke to the children who mention the mu herders living nearby which opens up the Mu Tundra village. Here I spoke to the man who mentioned that a dragon is giving them some problems nearby which then opens up the South Oubliette area. After completing this dungeon and defeating the boss, head back to Mu Tundra village and talk to the man again where they will now befriend you.