Location was excellent, within walking distances of 3 stations (Shinjuku, okubo, shin-okubo); apartment was cosy and clean, with washing machine provided and indoor bathroom drying available. Host is responsive to questions and check in guide was detailed.
However, each apartment is too squeezy to comfortably accommodate 3 people (would have been perfect for 2 people in a room) as there is not enough space for 3 luggages to be opened at the same time and allow for walking space.
Furthermore, the wifi dongle provided was not able to provide connectivity to both apartments, so it could only be used in 1 apartment at 1 time. However, the internet connection was fast.