The best airbnb place I've stayed in Tokyo during my trip. I only met Kazu when I arrived but he went through everything clearly and has a folder with all the details. His family lives on the first floor and the bottom floor is for guests with use of the toilet, bathroom and laundry washer. You get a private room with lock which is good.
Note, there is about two flights of stairs to get to the main door so you have to carry any heavy luggage up but not a major issue. Also no microwave but maybe Kazu will let you use his, although I always came back around midnight so never a good time to ask.
Location was great being two stops away from Shinjuku. It is just off a busy road so always people around and very safe.
The bathroom has a very large sink and shower for Japanese standards I think so that's a big plus for me.
I didn't realize until the last day there was so much around the station like a Mos Burger, McDonalds, Life supermarket, Sayziera Restaurant.
Also a 100 yen Plaza on the way to Kazu's place so great for things you need or last minute gifts.
Overall, good location, good amenities, good host. Would stay here again if I come back to Tokyo.