We (a group of four women) spend a few nights in Ken's appartment in March 19. We can absolutely recommend his place and a sure you would have a great time there!
It was convienently located just a few minutes from Sasazuka station (frome there it is minutes away from Shinjuku by train). The area is quiet and feels very safe. A few nice restaurants and good coffee places are in walking distance as well.
The apartment was super clean, towels and amenities were provided for each guest. The beds were comfortable and heating/ aircon came in handy since it was still quite cold in Tokyo. Ken responded to every request very quickly and was super helpful and friendly. Check-in and check-out were super easy as well. The pocket wifi was a great plus and helped us a lot navigating through Tokyo. Thanks Ken for a great stay!