Sohei's place is a fine option for travellers who are looking to leave their stuff and go wander. It is a little worn on the edges, not with the spit and polish of some Japanese places, but it was very useable. We stayed for five days and found it a little off the beaten track from the train stations, but found the buses easy to use and a great bakery just down the street that had room to sit and eat outside! Ghibli Museum is a very short walk away, as well as the rest of Inokashira Park, which is a nice touch. There are several convenience stores, but also a grocery store just down the street.
A few hints: it is a cheaper place to stay than some other places, so expect no frills. It is not such a user-friendly space for tall people (my husband is just over six foot, and he could not sit down on the toilet seat without his knees banging on the wall), nor for germaphobes (the toilet does not have its own washbasin, so all washing is done in the kitchen utility sink, and the shower room, though outside, does not have ventilation), but the air conditioning worked well and although we never used it, there was a movie screen and projector in the room, as well as a desktop computer. I'm not sure who the target audience is for those amenities, but I'm sure someone would find use of them.
I have had the good fortune to travel many places in the world, and I have certainly stayed in many places less nice than this one, but it was not exactly what I was expecting from Japan. For those used to hostels, this will be a great alternative, though, at a decent price point. It was a good size for two people; it could accommodate more if you are willing to fold up and put away your futon each night!