The owner was kind and allowed me to leave my luggage before the check-in time. Everything seemed well cleaned when I returned and I was very pleased with everything. Although I can imagine the ceiling being low in some rooms for tall people, it was much more spacious than I imagined from the pictures, especially for being in Japan.
I arrived late on both nights but noise wasn't a problem during the weekend that I stayed there; if anything, it was the same amount that I could (and would expect to) hear while in a hotel elsewhere in the city.
There is a convenience store just next door and the place already had pretty much everything you could ask for besides a TV, bath, and washing machine. There is only one toilet, one (small) shower, and one sink (apart from the kitchen sink), which wasn't a problem for me at all, but I could imagine being a little inconvenient if many guests are staying there at the same time.
I think the location is good if you are looking for a place near Sumiyoshi station. (I think it took me about 5 to 7 minutes on foot.) It's also not so far from Kinshicho station: one stop from Sumiyoshi station or maybe about 15 to 20 minutes on foot.