The cleaning of the place can definitely be improved: of course there is some dust and humidity due to the forest, which I could deal with, but there was even mold on the old shower curtain that, by the way, could be easily replaced. There is no possibility to leave the luggage there after check-out, even though in the end this is not a big issue, as going back to the place before heading to the station - where there are coin lockers - would require some extra time. Breakfast is not worth it, better have some in town.
This is a very good place to relax, as it is located in the woods near a stream, about 20 minutes walk/5 minutes by taxi from Nikko station and about 30-40 minutes walk from Nikko temple area. The inside onsen, with its big window on the forest, is small but it is ok for 30 minutes of relax.The lady running the place was quite nice, she replied quickly to my emails before going there and even drove me to the station after check-out. Of course, speaking Japanese helps the communication.