The room was perfect for 5 ppl! Very clean, near almost everything nice in shinjuku and the Shinjuku Station if you have the JR pass!
There is also a lot of restaurants and family mart (convinience store) near Kumiko's.
There's a refrigerator, sink, a nice cute little bathroom and a good pocket wifi. Also, there's enough place to put 1-2 extra futon on the ground (like crazy comfortable futtons).
In short, if you're looking for a nice and cheap place : Kumiko's the way to go!
P.S. : TRY COCO HOUSE ICHIBANYA! (10 min walking from Kumiko's)