The house is clean and with modern appliances. Our stay was comfortable. The house is close to two FamilyMarts and a Supermarket. We loved the convenience of it. Not to mention there's a soft drink vending machine just outside the house. I also love the laundry machine (two in one - washer and dryer). We didn't have to bring so much clothes. A couple things to note:
1) If you are planning to get to the house by taxi, please contact the host for the address in Japanese as our taxi driver couldn't figure it out and we spent double the time to find it.
2) Consider getting to Shinjuku train station by the #32 and #33 buses. For a few days, we walked to the train station (Nishi Shinjuku Gochōme Station). As two families with three boys and a stroller, it was a long walk in the heat and not to mention the inconvenience with the stroller. However, once we figured out the bus route, it was awesome. The buses come very frequently and it was easy. Definitely recommend traveling through the bus route. The bus stop was really close by too.
3) Some appliances (dish washer, laundry machine and the bath) would be difficult to figure out if you don't read Japanese. I was able to read some Chinese (Kanji) to figure out how to make things work. If you can't read that, I suggest you ask the host to give you instructions or translations on how to use them. Once you figure it out, it's a breeze.
We loved the house and would highly recommend it.