In Phantasy Star I, there is a town in Motavia called Uzo. The town is not on an island. Among other things, people there tell you about the frade mantle and the flute.
Fast forward to Phantasy Star II. There is an island called "Uzo Island". It contains no town called Uzo. You need to go there to get the Maruera leaves to open up Climatrol.
In Phantasy Star IV, there is a town called Uzo that is on an island. They seem to have been cut off from the rest of the island. Someone there tells you about how great the Frade Mantle is (just as someone did in PSI) despite the fact that the Frade Mantle in PSIV is not very powerful at all. Someone else there says they come from a long line of musicians and that one of his ancestors loved played the flute (which strongly suggests that this Uzo has a connection to the Uzo in PSI)
Anyone have any explanation for all this?