I have been to Tokyo multiple times, but this was my favorite place I have stayed at yet. The staff are all very helpful and have great recommendations for the area. My first day, I went to drop off my luggage before I checked in, and when I mentioned I was planning on visiting some bookstores that day, they immediately offered recommendations for their favorites.
The space itself is very cute with nice touches like embroidered numbers for the beds. The building is on a quiet side street, so it was never too noisy at night. It's only a couple minutes' walk from the nearest train station, but if you don't want to deal with the transfer to the local train line, it takes less than 20 minutes to walk from Ikebukuro Station.
I would definitely stay here again the next time I visit Tokyo.