Did kisame knew about obito's eye of the moon plan before the invasion of pain arc?Its certain that the other members including itachi,nagato and konan were unaware of it but did kisame knew?
I dont think so, cuz he wasnt their from the start... And he doesnt care as long as he can find him a vessel that contains enormouse amounts of chakra for samehada
Kisame new that his Mizukage wanted to "create a world without lies". However, he was unaware that Tobi/Obito/"Madara"/Mizukage was in control of the Akatsuki.