I wasn't even able to enter the building.
The place has no reception, which is fine, but the owner didn't send me the check-in instructions they were supposed to.
Check in time was 3pm. As I arrived at the hotel, I had the unpleasant surprise of seeing there was a lock in the door. A lock for which I didn't have the password cause the owner never contacted me, as they were supposed to, even though I had booked it over a month in advance. This is not mentioned anywhere in the listing, but if you don't receive the password there is nothing you can do because the check-in machine is inside.
I tried to contact the owner through the email posted on the door and waited for 3 hours in front of the hotel, but no response (I don't have a Japanese phone number as I am just a tourist).
I also contacted Hotels.com costumer service, but they were limited in how they could help.
Since it was my first day in Japan, it was raining and I was exhausted, I couldn't wait any longer and ended up paying for another hotel.
I finally got a response at 7:30pm with the check-in instructions that should had been sent long before. It was just a standard message though, no apology and no acknowledgment whatsoever of their mistake.
I am glad I was able to afford another hotel at short notice, but it was an awful experience and almost ruined my trip to Japan.
DO NOT BOOK THIS PLACE IF YOU'RE A FOREIGNER, communication is awful and you will be let down.