My partner and I stayed at this apartment recently and enjoyed our stay. This apartment is in a good location with very quick easy access from the Nishi Shinjuku station down a clean, safe and quiet residential street (located next to a junior school so be ready for the morning school jingles). There is a family mart close by and a few restaurants, the main area of Shinjuku is only around a 15 minute walk. The apartment has good amenities, everything you would need for a short or long stay.
Unfortunately there were some issues with cleanliness. At check in we found hairs on the floor and the walls had some very large dirty splash marks near the bin area of the kitchen, there were also a few large stains on the floor. We suggest better cleaning between stays... other than this issue we enjoyed the apartment and would recommend.