We loved this place! It is a contemporary architecture lover's dream with some clever solutions -- and a unique blend of traditional tatami sleeping (which we found very comfortable) and cutting edge contemporary style. This is the largest in a slim tower of around 5 stacked units and we especially liked our terrace with lounging chairs. The small kitchen allowed some light cooking, and the sofa for some western seating apart from the tatami area. The best however was the neighborhood. Maybe not in the thick of Tokyo sightseeing spots, but just a very charming neighborhood with narrow streets and an incredible assortment of street food vendors just steps away. Two Subway stations in easy walking distance let you reach most spots in Tokyo within reasonable time. And some places are quite close, such as Yanaka retro neighborhood, Sensoji temple with its market street, or Ameyoko Market near Ueno station.
Yutaka's units are registered as a hotel and managed through an agency. They were always quick to respond to our inquiries. When we arrived the wifi was not working, and an employee dropped by a new pocket wifi the same evening.
They do request that you send registration info and a passport copy before arrival via email, which I did not feel comfortable with. In the end, they were flexible and allowed me to send this by post. I would prefer a solution to register at arrival, like all other places we stayed in.
Overall we had a very enjoyable stay at this place!