We stayed for 1 month at Kazumi-san's apartment and can highlight the following:
Pros:
- Large bed which can easily fit 2 people. This is surprisingly rare in Tokyo and not a small thing for long stays.
- Great location, walking distance to Shinjuku station from where you can go anywhere. Plenty of good restaurants and shops nearby. The small shrine at the entrance of the alley really adds to the atmosphere.
- Clean place with everything you'd need for your stay.
- Very responsive host and can communicate well in English.
Cons:
- During winter it gets cold and the air conditioner takes a while to heat up the loft where the bed is located. It's fine if you take the 1-2h before going to bed.
- The stairs going to the loft requires some level of agility to navigate, especially if you're on the larger size. Anyone over 1,90m and 90kg will struggle a bit to get into bed.
Overall I recommend everyone try out life in Tokyo and Kazumi's place is a good home-base.