The Legend of Zelda: Twilight Princess

Which cat in which house?

if u find 20 poes, Jiovani can move some, and his cat can move too. Find all 60,
and Jiovani will go see his girlfreind. talk to the cat (As Wolf, of course) and he/she will ask you to find Jiovani. lok in Telma's Bar(?) and talk to jiovani. Go back to the cat, and the cat will give you 200 rubies per visit. nice way to get rich quick, and if you havent done the Second malo mart yet, thats a good purpose for finding all 60 Poes.

Do you mean the one in Ordon or the one in Castle Town?

For the one in Ordon, you have to catch a fish. Two, actually. If you go to the side of the river/lake that the cat is on and catch a fish, the cat will be interested, but won't come near you or the house. Catch another, and the fish will drop on the ground and the cat will take it to the house.

For the one in Castle Town, turn into a wolf and dig right outside Jovani's house. But that's not really getting the cat inside the house, it's getting you inside the house. xDD

Bite that cat's tail as a wolf, and he will run home.