This was the first place I stayed in Japan, and probably the best!
I stayed in a private room with an ensuite and was very happy. I had a double bed, my own bathroom (which looks like a caravan bathroom stuck in a room, but that seems to be the theme in Japan), a tv, an air conditioner and it was quiet!
The location is pretty good. Just down the street is the tram which you pretty much have to catch to get to the main shopping area, or the Hiroshima memorial park, but that's not too big a deal for the price. I walked from the train station to the hostel as well, so if on my first day after a 30 hour trip I could do it, so can you.
Great people, great value for money. I would stay at all of the K's houses in Japan if you can get in!