I stayed in Norie's dormitory in Nakano for almost one month. My exprrience was overall very good, I needed a cheap place that was in a good location in Tokyo and I didn't mind being a little uncomfortable. Once I got used to it, it was actually perfect for me. The space that you're given is small (and if you're tall like me you won't be able to extend your legs completely), but thanks to the curtain it's private and if you can organize yourself, you'll find out that you have everything you need while saving a lot of money. The room is also always fresh thanks to the air conditioner that you can turn on whenever you want. In addition to the private place where you sleep (that has a space to put your things as well), I was given a place to put my clothes and a small locker. Then, a drawer for my shoes, a drawer near the kitchen for my groceries and a place in the fridge. Talking about the kitchen, it's small but it has everything you need, but no microwave (I think there used to be one though). There are two washing machines and you have to pay 200¥ everytime you use them, which is ok especially if you organize with someone else in the dormitory like I did and you do your laundry together for half the price. Then, you have a place to eat with air condioner, television, an iron, computer. Wifi is usually good.
Around the share house there are lots of Convenience stores (also a Lawson 100¥ that will become your best friend) and a big supermarket. It's in a residential area so it's usually very quiet.
On a side note, if you come to Japan to study Japanese, staying in this share house could be beneficial for you because there are many Japanese girls, and even though they are usually very busy, they will probably find the time to speak with you a little.
I will probably come back to this share house next summer, it's very convenient and since I usually go out in the morning and come back at night, for me it's just perfect.