Both Mr. and Mrs. Fugu live in Kagawa prefecture, but they live apart from each other now.
The fragrance river prefecture is Kagawa Prefecture. Might help to look at the reading first.
This reading is made up of the kun'yomi readings for 香 and 川 (rendaku'd) and the on'yomi reading for 県. You haven't learned this reading for 香 yet, so here's a mnemonic to help:
If you want to get to Kagawa Prefecture you're going to need a car (か). It's all the way over on Shikoku island, and you won't be able to cross the big bridge without a proper car!