A blond girl who likes to call him "uncle" is proud, comfortable and generous; a white-haired uncle who likes to call her "idiot" is arrogant, free and pious.
They are enemies, but the difference is that Ino lost his memory and accidentally rescued Hidan who was buried in the Nara family's medicinal area. Hidan took Ino away.
[... Why do you feel like you are about to elope? Ahem, what will Konoha do at this time?