Kazutomi's place was exactly what I expected. Like many previous reviews, the location is a 15 minute walk to the nearest train station, and then 10 minutes to Shinjuku station. The walk is doable if you are traveling light, or don't mind carrying heavy luggage. Ideally in Japan, you should travel light.
The home is nested on the second floor, in a building located in a quiet and safe neighborhood. The stairway is very narrow, so we carried one piece of luggage up each time. The home is extremely clean; you will notice if you've made a mess very easily. Great amenities and kitchenware are offered, so you don't have to worry about basic necessities. The room is an easy fit for 2 people, but can fit three if you don't mind sharing a twin bed. The floor mat isn't thick so you have to be okay with sleeping nearly on hardwood floor.
Kazutomi is also very responsive. He kindly allowed us an extra 30 min late check out when we found out our flight back home was later than expected. He also provides instructions for the home, and travel suggestions in your room.
I recommend this place if you are staying for multiple days, don't mind the walk, and pack light.