Cleanliness: there was an issues with the bed sheets which did not look really fresh upon arrival. However, the host did try to solve this immediately. The bed sheets have been changed, however the other decorative pillows remained stained and dirty. Also the mattress and the blanket could have been much cleaner. Even if there are bedsheets covering them, the guests do not want to wonder what are all those stains on the mattress and blanket. Altogether, I had the feeling that the entire thing was very much streamlined and made efficient for the host, but not so much for the guests.
Another issue which will become more serious if it is not addressed is the smell from the bathroom. I have the feeling that the way this bathroom is made, it allows water to come in between the bathtub and the wall, with everything which comes after the people are taking a bath. All this probably accumulates in between the bathtub and the wall or underneath the bathtub and slowly but surely it starts to stink. There is a strong smell which is coming either from there, or from the pipes.
There were plenty of announcements what NOT to do with the garbage, however it was not clear where to dispose of the garbage. People visiting there are usually on holiday, they want clear indications about what to do with the garbage. And yes, I travelled to Japan many times, I know how strict and detailed the garbage sorting is, but other places have very clear indications and inside the unit there are containers for each type of garbage separately. Also, there is enough place outside to dispose of the garbage. Again, the entire thing is too "efficient" for the owner, but not so much for the guests.
The place is very small and the photos too "professional", suggesting more space, OK, here we may say that what we see is what we get, but ... I think the photos can be made a bit more honest. Also, when the place is so small, it would be good that the cabinets are empty so that the guests can store their stuff in there. Instead, part of the cabinets was occupied with a broken table, which was very much needed in the room. What is the use of the kitchenette if there is no table to eat on? Another large mattress was occupying parts from another small cabinet.
Good to know is that the place is a bit noisy as the street is just next to the building. For people who have a sensitive sleep, this might be useful information. Yes, the unit is indeed on a secondary street, but still there is quite some traffic there, also at night.
To the good parts: the location is very nice, easy access to trains and then to the attractions of Tokyo. Nearby is the Kagurazaka district, with nice restaurants and nice atmosphere. Also, the unit is relatively new (as of April 2019) but must be maintained more carefully.