I stayed in the dorm room with a friend, not partner, sharing a bed. It was overall a good experience, especially at the price point with such a great location.
The house is in general charming, but a bit drafty. Facilities are good, and there is a mini fridge and microwave oven available.
Dorm room: The bed size was fine, although you may have to bend your knees a bit if you're on the tall side (190+ cm), and it can get drafty, though the aircon (slowly) helps with that. The room can also get tight packed if you have multiple travelers with big bags, though we managed.
We had a small incident of me sitting on a bed curtain and breaking some plastic, but after a short correspondence with the host we worked it out.
There is a sake bar downstairs with a very friendly owner who speaks English and was very helpful although he does not seem to have anything to do with the hosting.
The 24-hour 7-eleven right next door was also extremely convenient.