I stayed 3 nights at Hikoro's place. It is in very nice Saint Germain neighborhood. You can find nice restaurants, bars, bakery, etc nearby. Tourist attractions like Norte Dame and Louvre are short distance away as well.
Her place is nice. Very smart design.. It is not a big place but space is smartly used.
As other reviews mentioned, her place is located in 5th floor and there's no lift in the building. I had no problem going up and down but it may be difficult for some people.
Hiroko was nice and she provided all necessary information.
She was easy to reach as well in case you need her.
I would highly recommend this place.