Haruko was very kind to us, and responded to all questions and concerns immediately. The location of the unit was excellent - just over 10 minutes from Nakano station with lots to do everywhere. The unit itself had all of the basic necessities for living despite being small. Check-in was simple, and it was convenient to use a combination lock rather than a physical key.
However, there was an issue with mould which we did not complain about. It is likely Haruko would have fixed the problem had we complained.
Overall, we enjoyed our stay, but would recommend requesting a proper cleaning of the mould before renting.