[quote=Masaki Haruna]
Mizukage rules the Hidden Rain, Land of Waves, Kirgakure in general I assume unless there is such thing as Ame-Kage.
[/quote]
I think Village Hidden in the Rain has its own leader, it was Hanzo (i think his name was) then Nagato and now its unknown. The Hidden Rain was its own separate faction, but I'm not too entirely sure on this