YK's place was as described, exceptionally clean, and near both a mini mall, restaurants and the metro. Throughout the stay YK initiated communication several times, welcoming, reminding about house rules, checkout time towards the end, etc.
We enjoyed staying six people for a week, benefitting from the code lock on the door as we went and came individually. As a group we took inspiration from the house manual which contained sight seeing suggestions.
I would stay at one of YK's places another time, although I would prefer a place closer to a JR station if I also travel on a JR rail pass next time I visit Tokyo. The walk to Ueno station felt a little long.