Stayed for 10 nights.
I never met Tomomasa in person but he reacted quickly to my questions.
The flat is small but for one person more than enough. For two people with big luggage it is probably to small. The flat also had a wash mashine which is not stated yet in the description. I loved the loft really! It really made the place so much more spacious! Shower, Kitchen and so had everything I needed, AirCon worked great.
The location is awesome. It is really close to Koenji Station and the neighbourhood is cozy and you get everything you need (supermarkets, daiso, cafe/restaurant, shopping (lots of vinted stores! but also more). Only thing to mention is, that the house is a bit older and the walls are REALLY thin. There are two more flats who are AirBnBs. Luckily, I had neighbours who were not noisy (most of the time) but you can hear and feel the neighbours wash mashine when in use. On some nights until 1am.
For solo traveler I can fully recommend this flat!