Pleasantly surprised at how comfy my single room is... it has the feel of a cruise ship cabin but is perfect for one person. Lots of nice little features such as every toiletry you would ever need, a mini fridge for drinks or snacks, convenient light controls next to the bed, an emergency flashlight, electric tea pot, individual control of air conditioning, secure access in elevators to guest rooms, a pleasant lobby and a great location. As others noted, there are convenience stores, restaurants and shops close by and it's a short easy walk to Shinjuku station.
When you enter your room, you won't find a light switch - place your key card into a cradle on the wall to turn on the lights and AC. This prevents leaving lights and AC on when you're not in the room and saves energy. There are also magnets available to place on the door to let the cleaning staff know whether you want fresh linens or just to have your room tidied. Thoughtful conservation features I appreciated.
My only complaint is the advertised free wifi is only available in the lobby and second floor guest lounge and the signal strength is not very good. The rooms offer free internet via cable, but my netbook doesn't have an ethernet cable port. If I had known this before traveling, I would have planned ahead instead of having to purchase a little wireless converter locally.
A caution - if you think you will be having anyone visit you in this type of room, be aware the bathroom has a large window looking into it and a clear glass door. (It is billed as a room for one person!)
Overall, I was very pleased with the clean, cozy room and the excellent location at bargain prices. My daughter and her boyfriend were staying in another hotel at triple the price and thought my room - though smaller - was very comparable.