This is a really nice accommodation. Practical, very clean, with all the basic necessary amenities and more. Convenience store plus super market around the corner. Yotsuya station is a 10-12 minute walk, Shinanomachi station (only local JR Chuo line) is a bit nearer.
Very nice bar & restaurant district near Yotsuya sanchome is also less than a quarter of an hour away.
All in all highly recommended. FYI, we were two adult couples.